In order to be a well-mannered traveler, you want to make sure not to offend the culture. You especially want to be careful in times of stress. If you find yourself in Russia, make sure to throw back your vodka. Sipping is considered rude.
Also, it may seem weird, but make sure to give someone an odd number flowers for everyday flower giving purposes. An even number of flowers means that you are giving someone flowers for a funeral. Make sure to smell AND count the roses while in Russia.