There are many things you have to take into consideration before and when you travel somewhere. This article presents travel basics and is geared towards people with comparatively little travel experience — this is not to say that experienced voyagers could not find it useful as well. More thorough information is available in the linked travel topic articles and in the destination articles.
Plan
See also: Concerns
This is the drawing board stage. It is about things that should happen in your head (and possibly in your conversations) and in your notebook, before you take the material steps to get ready to go.
Understand
When you travel, expect things not to be like they are "back home". Manners, laws, food, traffic, lodging, measurements, language, standards and so on will to some extent differ from where you live. This is something you always need to keep in mind, to avoid disappointment or perhaps even distaste over local ways to do things. When you communicate with locals it is often easy to utter remarks like "back in the US, UK, Australia, Europe (you get the point) we do it like this...." Avoid this, as it will make you a representative of everything your home country stands for, whether you want this or not. And there may be good reasons things are done differently.
Studying your destination beforehand is very advisable; in addition to Wikivoyage articles, Wikipedia articles and sites of local tourist offices, sights and businesses are good for this. The destination country's embassy is often happy to help you with travel information. Depending on the country, you may have to contact the embassy in any case to apply for a visa. Fiction books may also help to get a feeling for the place. Frequent travellers are often tempted to forego all planning, in particular if they've been to the place before. However, you never know if something has changed there or even at your home airport or railway station. It's useful to make a checklist so that you're sure you aren't forgetting something.
Pick your destination
Paris syndrome
Among Japanese tourists there is a well known phenomenon called "Paris syndrome" which basically boils down to people coming to an overhyped destination — classically Paris — with unrealistic expectations and then being disappointed to find that the hyper-romantic "best place on earth" image in their head doesn't match up with the often dirty, congested real city full of rude people. Doing proper research before travelling and having more realistic expectations can limit the risk of "Paris syndrome", but first-time travelers should always be prepared to have things be wildly better or worse than expected.
Where you choose to go depends on your own tastes and preferences. If you have a set time for when to go, choose a destination suiting the season (see Choose the time below). You may also have special needs, especially if disabled in some way, or traveling with children or pets.
If you are planning a trip with friends, discuss your travel plans a couple of times, allow everyone to have their say and be flexible, keeping in mind that people who are friends before a trip could be enemies at the end if anyone feels mistreated or disrespected. Also, everyone doesn't have to do the same thing at the same place all the time.
Disabled travelers or their travel partners should inquire about the possibilities of transporting aids such as wheelchairs or crutches as well as the overall disability-friendliness of the destination. If you have a pet, you should choose a destination where it is welcome and where you can handle any issues – if unused to travel, leaving it at home is probably wise. If you will travel with children, you probably want to go somewhere where they are welcome and avoid places where hazards such as crime, diseases and extreme weather are prevalent. Finally, if you travel alone, remember that should something bad happen, you will have to cope with it by yourself.
In general, prominent tourist locations are easy to get to and have good infrastructure to accommodate the influx of visitors, while remote destinations may pose a number of challenges. Consider the kinds of recreation, sights and facilities you want and what is available at the possible destinations.
Don't go to places where you don't want to follow local customs and laws. For instance if you as a woman don't want to wear a hijab (kerchief that covers your hair), some Muslim countries may not be advisable to visit. Furthermore, some countries have mandated sex segregation and stringent and even deadly LGBT laws. Certain political systems (e.g. North Korea) might clash with your views on how things "ought to be" done. Overall, things that are perfectly legal at home may be outlawed in your destination country (and vice versa). You should also check the safety situation in the country. In particular, if your embassy in said country has issued a travel warning, you should probably not travel there.
The local culture affects more than just your safety. Going to an environment radically different from your own may give you quite a culture shock, especially if you haven't done much international travel — keep this in mind when you choose where to go.
Language may also be an issue; as widespread as English is, there are many parts of the world where virtually nobody understands it. Even where they do, you may have trouble understanding their accent. And even where "everybody speaks English" there can be countless nuances you miss by not bothering with the local language(s). So now that it's easy to find online language courses, you owe it to yourself to do a little study if you will be travelling somewhere where English is not the primary local language.
Getting in and around
Main article: Transportation
There are as many ways of traveling as there are destinations. Usually you will travel with a combination of modes of transport, and it's very useful to have some information about routes, fares and schedules beforehand.
Choosing a mode of transportation is often a balancing act between expense and convenience. Buses are often cheapest, but spending multiple hours on a bus is usually much less comfortable than taking the train. The costs in time and money are not always clear beforehand: budget airlines can offer cheap fares, but they often use airports far outside city centers. If your €50 flight ticket means you will pay €30 for extra luggage, €10 for a mediocre meal and €50 for a taxi ride to your destination city, it might not have been the cheapest option. The €140 overnight ferry, with which you'd have avoided a night at a hotel, might have been a better choice after all.
If you are afraid of traveling by a particular method, it may be possible to get there another way or to attend a course or get therapy to overcome your phobia. Wikivoyage has some advice for nervous flyers, as fear of flying is common, although it's generally by far the safest form of travel. Airports
If you need to transfer at an airport, check that your connection isn't too tight and when going to the airport, boat terminal, bus or railway station, allow more time than you think you need. This is especially true when flying — in particular when there are international flights involved.
A rule of thumb says you should arrive at the airport an hour prior to boarding for short flights, two hours for longer flights (e.g. transatlantic) and an extra hour on top of that if going to or from someplace in the USA or Israel on your initial leg (due to their lengthy security procedures). Add another half hour if your initial point of departure is a big or particularly crowded airport or if you know the procedures of the airline you'll be flying on to be particularly inefficient. Plan at least another half hour of buffer on top of that, especially if it is your first flight. Due to late departure, weather conditions and congested runways, don't count on your first plane landing as scheduled. Also, you will still have to stand in line for customs, immigration and security.
Overall, unless it's a small airport, it's best to be at the airport at least two hours before departure. Don't worry about having to sit on the airport "for a whole extra hour" if you do get there in time and lines are short; if you miss your plane you will usually have to wait much longer (possibly have to pay for a hotel night or sleep at the airport) and in some cases buy a new ticket. Yes, you are able to book flight combinations that have just half an hour for transfer, but they are often a bad idea. Also, if you miss the day's last bus or train (in some cases you need to stand in line to the ticket counter...) into town, in the worst case you're in for an expensive taxi ride.
For some travellers, there might be a wish or a need to avoid entering the United States — even in transit. The Wikivoyage guide on this subject spells out why and how.
By definition, travel includes navigation, which means you will need one or several maps of some kind. Even if you travel in a group and follow a guide all the time, it can still be interesting to know where you are and where you will go next. If you are driving, a GPS navigation device can be practical and a wide variety of online services (such as Wikivoyage's dynamic maps) and offline apps for smartphones and computers exist. Paper maps can also be an option, as they do not need electrical power or an Internet connection. They have the drawbacks of becoming outdated easier than online versions and easily marking you as a tourist; on the other hand, there are still long stretches of road in places like Big Sur that have no Wi-Fi, and flashing an expensive smart phone or tablet on the street may well attract opportunistic thieves.
Choose the time
Some parts of the world are better avoided during certain times of the year due to weather conditions. For instance, tropical and subtropical areas almost always have a rainy season (which means it rains a lot). Rainy seasons vary from place to place but as a very rough rule of thumb they tend to coincide with the summer of the hemisphere you're in - a Northern hemisphere destination will more likely have a rainy season in August and a Southern hemisphere destination will more likely have a rainy season in January. Other parts of the world may have seasons for tornadoes or (while they not may be in the tropics themselves) tropical cyclones. Familiarize yourself with the local weather conditions for the time of the year you will travel. Remember that the seasons in the Southern Hemisphere are reversed from the ones in the Northern Hemisphere.
It is often wise to avoid local holidays, unless they are your reason for travel. Semana santa (Easter week) is a bad time to visit any beach destination in Latin America or Spain, as almost every local who can afford to travel will. Similar things can be said for Thanksgiving weekend in the US and the Chinese New Year in much of the Far East. When travelling in Europe, check out when schools are closed for vacation. In less touristy areas there may be the reverse problem: especially small establishments are often closed during the local holiday season. In general, places locals travel to will be crowded and open during peak travel season whereas places locals travel from during peak holiday season will be closed for the holidays.
While peak season might mean that everything is crowded and fully booked, this may also be the most comfortable time to visit considering the weather and your work or school schedule. In low season, while prices may be cheaper, you may find that points of interest are closed or on reduced open hours, and the weather may not be as inviting. On the other hand travelling in the low season can be very rewarding. For example in Venice before and after the summer holidays the day temperatures are more pleasant, and the city is not overcrowded. In Marrakesh or Madrid it is very hot during the summer holidays and more pleasant in spring and autumn.
Ticket prices also vary depending on when you travel and often also on when you book. This is especially true for plane tickets but also applies to long distance train and bus tickets, which can have vastly different prices depending on when you book, especially in some high-income countries. If you're going for a short trip or will travel around a lot, ticket prices may make up the largest part of your budget. If you have alternatives, shop around a bit. You can save a lot of money if you are flexible with your dates. Also, when booking plane tickets, there are maddeningly diverse and sometimes logic-defying ways of saving money (or not getting overcharged), which are spelled out in greater detail in the Wikivoyage guides on budget travel and in our series on flying.
Plan a schedule
See also: Time management
Having answered the questions where, how and when, it's time to plan a schedule. A good basic travel plan is a list with times of arrival at and departure from the places you want to visit and transportation details. This can also function as a schedule; you may want to have an idea of how much time you want and need to spend at each destination before going onwards.
Make sure you don't only have time to visit the sites you've planned to visit but also some time to spend on places you discover once you've arrived and some down time to relax. Read up on your destination beforehand to avoid a bad surprise. It's not fun to realize that there is much more to see and experience than you'll have time for, if you didn't know that before you arrived (if you did know that, just enjoy what you can in the time you have and consider coming back for more when you can). It can also be quite annoying to learn after your trip about some interesting site that was just a couple of blocks from your lodging, especially if you don't have time/money to return anytime soon. Also, you may want to have a list of day trips if you find out that the attractions you've planned to go to are closed, otherwise inaccessible (e.g. astronomically long lines) or even don't live up to your expectations and you therefore wouldn't care to stay there for as long as initially planned. Many famous destinations are crowded in the middle of the day but can be quite deserted early in the morning. Masada, the last stronghold of Jewish resistance to the Roman Empire in 74 CE, has a cable car that gets you up there without breaking a sweat, but if you wish to catch the incredible sunrise, you'll have to hike up yourself.
You may face a dilemma in regard to train tickets: Tickets for off-peak days and hours booked far in advance with little possibility of cancellation or change tend to be the cheapest option, but you may find that you want to cut your stay at some places short while extending it at others — which may mean in the worst case you'll have to buy new tickets at more expensive prices and lose the money already spent. Luckily there are rail passes like Interrail that allow quite extensive and flexible travel at relatively affordable prices. Both Japan and the US also have similar offers. You could also choose to rent a car or check bus prices for greater flexibility, though bus tickets often have the same issues as train tickets and extending a car rental can be expensive and sometimes impossible.
Prepare
This is the intermediate stage between having things planned out and travelling. It is about the real, material, steps that need to be taken before you leave the doorstep.
Get paperwork ready
Main article: Border crossing
Crossing a border (intact and with all your things) mostly boils down to the question of whether you have all the right papers. How many documents you need and how difficult they are to obtain varies a lot. In most cases, travellers need a passport – travel by EU citizens within the European Union being one of the few exceptions. If you have one, check the expiry date, as many countries require your passport to be valid for six months after the date you expect to leave the country. If you need a visa, in the best case the application and issuance process will take a couple of days, but it may take much longer. In the case of small, less traveled countries, don't be surprised if it takes over a month to obtain a visa, and their nearest embassy may be in another country than yours. Also, if your country is poor, politically unstable or has tense relations to your destination, many countries might want to research your background thoroughly. If your trip includes several countries where a visa is required, remember that your passport can be at just one embassy at a time. It's often possible to get your visa faster (for a relatively steep fee), but if you can apply early enough, do so and save the money for something fun on the trip instead.
Sadly, some places cannot be visited easily in succession or by nationals of certain countries. This mostly concerns Americans in Cuba and travel to and from Israel in combination with certain Arab and Muslim states. Our article on visa trouble has more information about this issue. Trouble can arise also if you are in the process of changing names (such as because of marriage), your names are written in different ways, you have more than one citizenship, or documents otherwise do not agree on your person
Visas may be needed also for countries you do not visit on purpose: some countries require visas also for flight passengers just transferring or landing for a fuel stop. Planes can change route because of bad weather or the like, and end up landing in a problematic country.
For some visas (or for not being turned away at the border), you may need to show a return ticket, proof of booked accommodation, proof of sufficient founds and the like, to show that you are going to pay for your stay and not travelling to get a black market job. Some of this may require some extra time before you can apply for your visa. Check.
If you bring anything valuable, you may need to fill out a declaration on what you already own and get it stamped at a customs office before leaving (or ensure you have adequate other evidence), to avoid problems on return. You may want to declare the items also at the border, using the local forms.
Likewise, if you need to bring any medication, bring it in the original packaging together with the prescription or at least the receipt. Things you can buy in any supermarket at home may be illegal or require a prescription at the destination. If this may include yours, check import rules and bring enough for your journey (even if it gets prolonged for some reason) or check how to complement your supply.
Travelling as a couple or a family, you may need to be able to prove your relationships, if suspicions arise or regardless. You might need a permit from custodians (or the other parent) to travel with a child. Where there is severe sex segregation, a mixed company may not be allowed to share a room unless they are family, by the local definition. Unmarried couples might rely on the don't ask, don't tell practice, which can be risky in some places.
The global COVID-19 pandemic continues with regional variations. Different countries have enforced different policies for international travel. Please check that your vaccinations are satisfactory for your destination, and see what tests are required.
Check cancellation policies, your insurance and backup plans, both for the case where your plans change (because of illness or otherwise), and the case where some connection is cancelled.
Book
For more information on booking accommodation, see the Sleep article.
If this is your first long journey, if there is a language or culture barrier or the journey is otherwise beyond your experience, you might consider paying a premium for a travel agency. They can provide a package for transportation and hotels, an all-inclusive tour where some or all meals are included, and they can help you plan your voyage and do the bookings you want.
In the 20th century, a travel agency was the normal choice for long-range travel. Today it is usually cheaper to book transportation, hotels and activities directly (or through aggregators) yourselves. There are still pros and cons, with travel agencies having some cheap deals and taking some responsibility should your plans get upset.
Accommodation should nearly always be booked, and transport tickets are often cheaper when bought well in advance. Some activities that might require reservations and perhaps a degree of payment in advance are tables at high-end restaurants or tickets to attractions during high season.
Guided tours can be of different lengths, from a casual city walk to a cruise or safari.
Many hotels, restaurants etc. can be reached by phone, e-mail and web forms. For straight-forward bookings, the web form is often efficient for both parties, but sometimes you want to ask about things the web form doesn't allow. An e-mail exchange may take days, but you can more easily make sure you get understood than by a call in a language that either party might not master (or with strange accents over a noisy line). You can also show that you really agreed on a certain arrangement. Calls are still the most convenient means in many cases.
Some types of services, including accommodation and car rental, often require your having a credit card, for them to get payment for extra expenses, such as using the hotel's phone line or crashing the car. Sometimes a credit card is required even for booking simple tickets, especially when the local ways of paying aren't available to you (such as when only local debit cards are accepted).
Get insured
Main article: Travel insurance
While your homeowner's or renter's insurance may include travel insurance, it is oftentimes a very rudimentary one. Travel lasting several months, cancellations and medical evacuation are often things that are not covered — contact your insurance company well ahead and buy a proper travel insurance if needed. If you're not covered and have to pay out of pocket, it is guaranteed to be more expensive than the price of a travel insurance policy, and if something more serious has happened, easily several hundred times. Some credit cards also include travel insurance, but conditions often apply. Some countries require certain types of travel insurance with a minimum amount of coverage.
If you have medical insurance either from a national plan or a private insurer, see what their rules are for medical incidents while traveling. You may need to buy additional insurance. If you have any medical conditions, look into reasons that insurers might exclude you — for example, if you are taking a drug and the prescribed dose changed recently.
Learn basic phrases
Main article: Talk
When travelling in countries that don't speak your native language, you could learn 10 basic phrases that could come in handy when you're travelling. Wikivoyage has a variety of phrasebooks to get you started. Using your hands, smiling and playing charades are other useful ways to communicate.
In addition to helping you learn some key phrases, a phrasebook can be used when you need to say something: when you find the right sentence you could either speak it out or (especially if you cannot pronounce it intelligibly) point at it. Have the names and addresses of your hotel and other important destinations written down to be shown to taxi drivers and the like.
Also where you know or can learn a usable language, there are some tips that may help you get along.
Staying healthy
See also: Stay healthy
The more "exotic" your destination is, the more likely it is that you will need one or more inoculations, though countries that aren't tropical may carry risks such as hepatitis A or B or tuberculosis. Research beforehand.
Yellow fever vaccinations are required in quite a few countries as a precondition for being let in. Some groups may be exempt from the duty to get vaccinated. In other countries, proof of vaccination is required if you had previously been to an afflicted country.
If you need to use some kind of medication regularly, bring the amount of medication you will need on your trip, as prescriptions are seldom valid abroad. Furthermore, you may need a certificate from your doctor and/or pharmacy to show to Customs when entering the country. Some drugs are illegal to import to certain countries yet available over the counter in others.
Trips to a time zone different from your own may cause jet lag. As your body is in sync with your home time zone, a difference of three or more hours (though this varies from person to person) can make you feel tired, give you sleeping difficulties at the destination and in the case of really large time differences — as in Europe to the US West Coast or Oceania in one flight or vice versa — may even make you think you've got some disease. Fortunately your body will eventually adjust to the local time (often about 1h difference/day). Jet lag is seldom an issue when you travel overland, as your progress is much slower.
If you have pre-existing medical conditions, they may affect travelling in various ways. Firstly, some destinations and environments may feel uncomfortable (culture shock, steep terrain and strong sun). You may not be able to take care of your needs like at home. Even before you've started the trip you may stumble upon problems, as it may be difficult for you to obtain proper travel insurance. Finally, in visa applications for some countries like China and the USA applicants are asked if they have communicable diseases or mental health problems.
Money
Main article: Money
If possible, it's good to get some local currency before your trip, if only to get from the airport to your hotel. If you cannot get local currency, you might want to bring cash in a currency that is easily exchanged at your destination – your Faroese banknotes will hardly be recognised in Peru, and Peruvian sols can be difficult to exchange in the Faroe Islands.
You may not want to bring all the currency you need on your trip in cash, provided it is possible to use a credit or debit card at your destination. Check whether you need to inform your bank of your travels or change account settings, as sudden usage of your card in a foreign country may be interpreted as the card being used by someone else than you, and the card being blocked as a security precaution. Also, know that the risk of your card information getting into wrong hands may be greater than at home. If you have several payment cards, pack them at different places so that you in the case of theft or robbery still have one left.
Pack
See also: Equipment
What you need to pack depends on where you're going and for how long. Most travelers tend to bring more than they really need. Checking overweight luggage on a plane is usually very expensive, it can feel very heavy indeed after you've hauled it for an hour, and you can usually purchase the same or comparable items at your destination, anyway. It's also usually possible to do laundry during your trip, even if you need to do it by hand in a hotel's sink and hang it in the shower overnight. Travel light — that way you will also have room for some souvenirs to bring home. If you're visiting someone who'll appreciate you bringing a gift, you can pack roughly as many gifts on the way there as you intend to bring home in souvenirs on the way back.
If you are traveling internationally, check out the relevant country article for regulations on the goods you may import. The importation of medications and many foodstuffs, especially those which are unprocessed, is often heavily restricted. Many Muslim countries prohibit bringing in alcohol, pork, items considered pornographic or indecent, and religious material such as bibles. In some cases "political" material may be banned too, such as material from one Korea when visiting the other.
Electrical devices you pack may need to be special-made for coping with different standards, or may need adapters, converters or transformers. At some destinations power is unreliable, with spikes and outages. Check Electrical systems of your destination. If you pack video, also they may have issues with different standards and producer-imposed limitations.
If you intend to do all or part of your trip on foot or on bike, weight becomes an essential consideration. Outdoor stores have all kinds of weight reduced options of whatever gear they offer – often a small weight reduction for quite a hefty price, but for some people every gram counts, and for some items you can spare quite some weight and space. Another issue is whether you are comfortable with your luggage. For hiking a backpack works best, for cycling, try and pack the stuff into panniers or a trailer while keeping the center of mass as low as possible.
Travel
So, everything about the trip itself is set and ready. However, before you go, there are still a few things to do at home — see our getting ready to leave article for this.
Go
Depending on how you travel, there may be things you need to know about your transportation and crossing borders, especially if you're flying. Have a look at those articles as well as the corresponding Wikivoyage article of your destination(s) and the country/countries it's/they're located in to avoid at least some surprises you may encounter. There are also things you need to keep in mind when arriving in a new city or any other new place for that matter. Especially if you're an inexperienced traveler, you probably would like to have done your travel arrangements beforehand to avoid having to search for the safest way into town, lodging, and such after, say, a long flight and tiresome border check.
If you at home don't use local public transport or long-haul buses, trains, ferries or whatever means of transport you are going to encounter, or if the culture or milieu at your destination is different from that at home, you may want to read up on what to expect.
You probably know that some countries drive on the left and others drive on the right. Typically that means that everything else about driving (the layout of the car, right of way for turning) is mirror reversed as well. If you're planning to drive in a country that uses the opposite side of the road, it'll take some getting used to, especially turning. Many a tourist has ended up going the wrong way on a divided road after a turn—not a situation you want to be in! This doesn't just affect drivers: bicyclists will have the same adjustment to make, pedestrians must be alert to which direction cars will come from, and bus riders will need to wait on the opposite side of the street from what might be intuitive.
Buy
Main article: Shopping
If going someplace where a different currency is used, familiarize yourself with the exchange rate and what certain things usually cost. You don't want to fall out of the airport exhausted after a seven hour red eye flight and wonder whether 100 Nicaraguan córdobas for a Coke is getting overcharged (it is) or €2 for a döner is a bargain (it is).
If there is no price tag, ask for the price first. After doing this several times, you will find a way to do that in an elegant way.
Don't buy souvenirs at the first place available, in particular if they are touted as "real antiquities". Most likely you'll be paying high prices for cheap copies or forgeries. Also a "special price" or "discount" often means that you are being fooled. At the other end of the spectrum, if you've actually (whether you know it or not) purchased real antiquities or the fakes are too well done, you may face problems when bringing them out of the country. If you are interested in doing such purchases, do so only with established businesses and inquire whether you need a permit from the government to export them.
Some countries have a strong culture of bargaining. Read up on this beforehand, as the initial price may be several times the normal price.
There are also be things that may be illegal for you to bring home from your trips, such as coca-flavored products from Peru.
Stay safe and healthy
Traffic accidents, food poisoning and sunburn may be risks in countries that are otherwise safe. You will never get a sunburn at the beach, when you dwell and swim there only in the first and in the last two hours of daylight. Remember that medical help may not be as easily available as at home and often entails much more bureaucracy.
Unfortunately major tourist destinations often attract con men and touts who cheat money out of gullible tourists. Read up on common scams and have a clue of where you're going and what things really (approximately) should cost.
Embassies and consulates usually have no obligation to help you get home if you've run out of money, lost your tickets or such. At the end of the day, expect to be entirely responsible for your actions. Even if the embassy would arrange for you to be sent home, they would still bill you afterwards.
Travelling with children
Main article: Travelling with children
Travelling with kids raises a whole set of new issues. Check out our article for some helpful tips. It may be helpful to involve them in some of the planning in age-appropriate ways. If the children gripe a lot about something, you might be able to remind them that this or that is what they wanted after all.
Respect
Main article: Respect
As a traveller, you're a guest, and thus ought to respect the locals and their manners and laws. Even if you're at the most touristy resort and you've paid for your stay it doesn't mean that you'd have the right to do anything you please.
In many countries there are ongoing or historic conflicts between ethnic groups, regions or countries, or any number of other factions. These, politics in general, and a slew of other issues, may be very touchy subjects. In some cases your being seen as belonging to or defending the wrong group or standpoint may set a stop for a beginning friendship or even put you at physical risk. Tread lightly, listen rather than comment if such subjects pop up, and read up on subjects that might be taboo, to know what to look out for.
Even if you usually cannot exactly blend with the locals, you might not want to stay out as an obvious tourist. Especially in some areas with bad experiences with your countrymen or country, or tourists in general, it may make making friends (or having friendly chats) with locals more difficult, and it may turn you into a target for touts and thieves. You might want to rather try to look like a countryman of yours who has lived in the country for a few years.
Avoid awkward situations and don't use words and expressions if you're unsure of their meaning or the appropriate situation to use them.
Remember that what's legal at home may be illegal abroad. This includes things that are basic rights at home, including criticising authorities and showing affection. And sentences for what seem like minor offences can be really harsh. Citing your citizenship won't help in that situation (your embassy can get you a lawyer, but not much more).
Although foreign law applies to you when abroad, your domestic law can apply as well. You may be sentenced in your home country for having committed a crime, even if it's legal in the country where the deed has taken place.
If you are going as a group, make sure your expectations meet and that your programme suits everybody. Don't make an itinerary requiring lots of walking unless all of you are up to it. You should make some compromises, but also make sure everybody gets to see and do things that are important for them. If some want to go shopping and some want to spend a day in a certain museum, then perhaps you should do that, and meet again only in the evening. If your interests differ too much, perhaps you shouldn't do this journey together in the first place.
This includes expectations on spending money. Some may have to use all their available savings just to be able to do the journey; splurging out at that Michelin restaurant might be a disaster for them. Somebody else might want to spend when on holidays, or get their journey spoiled if having to overnight in a hostel with people still dropping in after midnight.
Prepare, so that you don't need the group to change their programme because of you: if you get miserable because of bad footwear, insufficient clothing or because you were not prepared for the rain, somebody may miss the intended highlight of their journey, as they don't want to leave you alone in the hotel.
Cope
Young travellers on their own may have special issues to cope with. In most countries people under 18 years of age are treated as minors; some countries have other age limits. In many countries places that sell alcohol are off limits for minors or young adults, and that may include the place where you intended to have your dinner. You may have to cope without a credit card, and make arrangements when one is needed. On some Baltic Sea ferries, minors are not allowed to board without adult company, and similar restrictions may apply elsewhere; car rental is often limited to people above 21 with sufficient driving experience. Young females may have problems with unwanted attention (or worse), and may need to take special precautions. Any young person may be more vulnerable to scams and robbery.
Return
Main article: Returning home
When shopping, remember that you may not be allowed to bring some things home – or to a country inbetween – such as certain threatened animals and products thereof, antiques, drugs that may be legal abroad, and pirated goods. Likewise, your country may restrict import of unprocessed food products. More often than not there is also a limit on the worth of the goods you are bringing in as well as separate restrictions on alcoholic beverages and tobacco.
If you travel by plane, don't exceed weight limits (if you are close, don't pack wet clothes!), and remember that liquids over are not allowed in hand luggage. Pack them in checked luggage instead, keeping them shut tightly and well insulated from the shock of being thrown around, and if you will be transiting somewhere where you need to exit the airside, forget about any purchases of liquids (beverages, perfumes etc.) from the tax free shops at your first airport.
As many currencies include coins that are worth non-trivial amounts (e.g. €2, CHF5, CAD2) be aware that coins cannot be exchanged and either spend them before you leave, donate them at your point of departure (airports often have special charity boxes for that purpose) or take them home as a souvenir or for use on future trips (if and where legal; some countries ban export of their own currency or set laughably low limits for said export).
If you've used your credit or debit card during your travels, compare your receipts with your bank statement to make sure there have been no unauthorized charges.