In the US, it is polite to:
- Show respect by looking someone in the eye.
- Obey laws without negotiation.
- People point with their index finger not the middle finger.
- Knock on an office door before entering. Wait to be invited in or until the previous guest leaves.
- Make appointments before visiting a friend at their house or an office building.
- Use quiet voices inside businesses.
But, it is NOT rude to:
- Greet children by touching their heads.
- Use either the left or the right hand.
- Show the soles of the feet or the bottom of the shoes.
- Sit or stand with a relaxed postures; do not think your listener is inattentive because she is relaxed.
- Talk when there is silence. Americans are uncomfortable with silence.