American greetings are generally quite informal.
Americans may greet you with "Hello", or "How are you?" or just "Hi".
The formal way of greeting is "How do you do?" and shake hands.
The eye contact is important when shaking someone's hand.
When you are having a conversation keep your distance. The americans do not like to stay close to someone when having a conversation.
Americans smile a lot. They like to have their smile returned.
