I think the ones that surprised me the most was the finger wiggle meaning "come here" was also considered vulgar and you can easily guess what it means.
But the weirdest ones were from a friend who went to India, who said you didn't wiggle your finger to mean "come here" but you waved your hand palm down in front of you. That makes NO sense. The other one is to make a loud kissing sound, lips pursed strongly with a head movement. I don't think they get how much that would PISS OFF Westerners.
Lastly, there's this thing about FEET. As in, you don't show the bottoms of your feet, so you don't sit with a leg crossed - the person your foot is facing, it's considered rude although I don't know why. You NEVER prop your feet on a desk. I think this is related to throwing shoes and hitting things with your shoe.