People from India tend to speak too quickly and mellifluously. Some Americans will have difficulty understanding you, because it will sound like one continuous stream of syllables to them. If you are having trouble communicating, try to enunciate and articulate each word independently of the others.
It is important to maintain eye contact during a conversation. Looking away is a sign of embarrassment or boredom.
Americans dislike silence in a conversation, and will feel awkward and uncomfortable if there are long pauses. If you fall silent in contemplation, they will feel the urge to fill the silence with chatter.