Since the interviewer's job is to make sure that not only your skill, but your personality as well, is a good match for them, you must establish rapport with the person or persons interviewing you. That begins the instant you walk in the door. Let the interviewer set the tone. Nothing is as awkward as offering your hand and having the gesture not returned by the other person. Therefore you should wait for the interviewer to offer his or her hand first, but be ready to offer your hand immediately.
Some experts suggest talking at the same rate and tone as the interviewer.
For example, if the interviewer is speaking softly, so should you. They say that body language gives more away about us than speech. Eye contact is very important but make sure it looks natural. A smiling, relaxed face is very inviting. Hands resting casually in your lap rather than arms folded across your chest also is more inviting.