Don't botch the slang.
Never disrespect the dialects, the Queen, or LOTR.
Feel free to go barefoot, but don't swim, apparently.
Don't tip anyone.
Don't forget to remove toilet slippers or wash your private parts.
Don't get overenthusiastic about nudity.
Never compare them to Sweden.
Make sure to give an odd number of flowers as a gift.
NEVER wear your outdoor shoes inside the house.
Don't ask about Russia's history or politics.
Katherine Makhalova: Don't criticize Soviet Union when talking with people over 40. They grew up in those times and might be nostalgic. Even if they enjoy modern life they might not like hearing foreigners talking about it. Don't assume we support everything our government does. Quite often we don't. Don't criticize our government. We do it a lot by ourselves, we don't need your help with that.
Don't touch the top of anyone's head.
If you have to point, use your thumbs.
If you're a woman, avoid touching monks.
Try not to kiss or hold hands in public.
Don't touch anything with your feet.
Get the language right.
Remember, Hakuna Matata is not just a Disney song.
Don't do anything Nazi-related.
Don't wish people an early happy birthday.
No shoes, no shirt, no religious service.
Don't mock Buddha.
Don't assume everyone lives in igloos.
Don't do anything with your left hand.
NEVER walk in the bicycle lane.
Don't turn down food.
Drink coffee the right way.
Don't visit places on national holidays.
Don't give clocks or umbrellas as gifts.
CORRECTION: Russian custom is to gift an even number of flowers. An earlier version of this post misstated that Russian custom is to gift an odd number of flowers.