To wave goodbye or hello to someone, raise your hand and wave it from side to side, not front to back. Wave the whole hand, not just the fingers. Waving the hand front to back or the fingers up and down means "no", "stop", or "go away". Holding your hand up with the palm facing forward but no movement means "stop". Holding your hand with the palm toward your body and wagging the fingers toward the body means "come here". Holding your hand with the palm up with all fingers curled and repeated curling and uncurling the index finger means "come here".

If you want to point at an object, extend the index finger and use it to point at the object. It is not polite to point at people.

If you want the waiter to bring the check, make a writing gesture with one hand as the pen and the other hand as the paper. If you just want the waiter to come, make eye contact and raise your hand.

Shaking your head from side to side means no. Shaking your head up and down means yes.

Never show your fist with the middle finger extended. This is an insult. Shaking a closed fist at someone is also rude, especially if it is in their face, and is an expression of anger.

Although showing your fist with the thumb up or your open hand with the tips of the thumb and index fingers together forming an "O" means "ok", this is an overused stereotype. Americans understand this gesture, but it is mainly used by actors in movies, not in real life.

It is not polite to pick your nose or chew your fingernails in public. Likewise, it is not polite to pick your teeth (with or without a toothpick) in public.

Patting a woman on her rear end is not appropriate, and will likely get your face slapped.

Winking at a woman is also inappropriate because of the flirtatious nature of the gesture. In other circumstances a wink will signal amusement or that the speaker is kidding. Because of the potential for misinterpretation, winking should be avoided.

When smiling, it is normal to bare your teeth, so long as the facial expression still looks like a smile, not a grimace.