[Blueface]

When I conducted massive amounts of interviews, I looked for this in the applicants:

Look the interviewer in the eye while you do a firm handshake and repeat his name in your greeting.
e.g. "Pleasure to meet with you Mr. ".......".

That is the very first impression you will make and you will appear confident.

Listen to the questions and answer them. Don't dance.
Best if you can answer the questions giving one specific example of when that took place and how you were able to handle it. Name the situation, your action and the outcome as result of your action. Shows you are qualified.

Be prepared to ask pertinent questions of the interviewer that will show you have researched the company and the position and are further inquisitive.

End with confidence. State you look forward to coming on board (if final interview) or you look forward to receiving a call for a follow up interview.