Gestures are so different in other cultures that they are in fact an altogether different language. It is safest not to use them until you are sufficiently familiar with that other culture. There are after all several cases where the same gesture has a radically different meaning...
Here is a Japanese example: you form a circle with thumb and forefinger to express that something is O.K., but your Japanese conversation partner looks flabbergasted, because in Japan this is a gesture for money... In other words, you make the impression you want to be paid (or bribed), which can be quite destructive to a fruitful negotiation.
Another good one is when you see your Japanese friend flapping her flat hand up and down at the wrist. No, she is not waving goodbye, on the contrary, she is beckoning you to come!
And don't be shocked when your Japanese business partner shakes his fist at you. It does not mean he is angry, he is only playfully telling you that you are stingy (literally "close-fisted")!
Also, when your friend is waving her hand in front of her nose, she is not chasing away the occasional fly, but she is telling you NO.
Some other gestures cause less confusion, but are useful to remember: for example that the Japanese point at themselves by pointing at their nose, not their chest. This is not a comical gesture, but quite normal.
Sticking up the hand in front of the face or chest with the palm facing left means that someone is apologising for crossing your path - it is not a pushy make way sign, but instead very polite, especially if accompanied by a slight bow of the head - something you can use yourself to good effect.