I honestly believe that one of the most important things you can do is to learn a few words in the language of the country you’ll be visiting. It goes a long way and people tend to be friendlier if you at least try to say hello, please, and thank you.
Here is a great little infographic from Living Language:
Whether you buy a small pocket book with useful phrases or simply remember how to say “Hello”, “Please”, and “Thank you”, it’s always useful to know a few words in a different language. It’s also the first step to learning a language!