If you need to take medication with you such as travel-sickness pills-keep it in its original container. If you need prescription drugs, bring a letter from your doctor. If you don't have a letter, customs officials may ask you a lot of questions at each destination.
Buy a guidebook and read about the local culture of the country you will be visiting. Also, try to learn a few basic words and phrases of the local language Don't assume that everyone will speak your language, or that they will understand English