After clothes, medication is probably the most important item to pack on vacation. Start with any prescription medication you may need, and make sure you have enough for your entire trip. Then pack more generic types of medication: vitamins, pain relievers, laxatives, antacids and motion-sickness medication. (Specific airlines may have restrictions on medication; check with them to see if you need to put it in your luggage or in a carry-on bag.) Insect repellent is usually a good idea, too, as is sunscreen. If you wear glasses, bring a spare pair in case they break; the same holds true if you wear contact lenses. Finally, if you're traveling abroad, see which diseases are a concern at your destination and get all your shots updated before you leave.
Documentation includes any paperwork you may need for the trip, as well as personal identification and means of currency. You'll need your travel tickets, both to your destination and for any transportation you need when you get there (rental cars, train tickets, etc.). Bring your passport, visa, driver's license and more casual forms of ID such as business cards. Carry a copy of your medical information with you, as well as a list of emergency numbers. Include maps of your destination, travel guides and any directions you may need. Always carry safe currency, such as a credit card or traveler's checks. Finally, include some secure means of holding your important documents, such as a belt wallet or something you can hide under your clothes.
Miscellaneous practicalities include anything you might need when the unexpected comes up. It can include sunglasses, a small flashlight and an all-purpose tool or Swiss army knife. (Note that such equipment will not be allowed on carry-on baggage when you're traveling by air, and you should probably pack it with your luggage.) Add a small tube of crazy glue and/or a mini-roll of duct tape for making impromptu repairs. Ziploc bags can help you store wet things, and make provisions for unexpected weather such by bringing a traveler's umbrella and a warm sweater. Finally, because travel often entails wait time--and you may not be able to recharge your portable game system--include some low-tech means of passing the time, such as a deck of cards or a good book. If you have kids, bring along similar games for them or other activities, such as puzzle books.
