Have a friend go over the questions with you until you are able to answer them promptly without stuttering. Give the interviewer a firm handshake. Give the interviewer a firm handshake, even if the interviewer is a woman and you are man. Nobody likes a limp handshake but by the same token do not take the person's hand off either. While shaking, introduce yourself keeping eye contact at all times .
Nothing is worse than an interviewee who looks depressed or indifferent.
Maintain Eye Contact at all times. You are confident about yourself and your capabilities. Do not stare out of the window or fiddle with your pencil. The interviewer is talking to you or you to him. Do not mumble your words.