I posted this on Fluther before, but:
most line supervisors hate to be interviewing people. They are interviewing because they have an opening to fill, not because they are screening candidates for future use. Every hour that they spend on an interview is time that has to be made up in order to do their own job.
Therefore, you don’t want the interviewer to perceive that his or her time is being wasted. The interviewer is counting on the fact that YOU are the answer to his problem, so that he or she can get the position filled, relieve whoever else has been covering while the spot is open and get back to his or her own job. The interviewer has his or her fingers crossed, hoping that you are the one.
Make a good first impression, smile, firm but not overwhelming handshake, be pleasant, look around the office for a second so you can get comfortable with the environment and being in the presence of the interviewer.
Some people will tell you to answer a question quickly and not hesitate. I think that this is wrong. You may delay some answers by a few seconds, you don’t make snap judgments in the workplace all of the time, why do it in the interview?
But the most important thing is to BE YOURSELF. Putting on any kind of false attitude or pretense can sink you because most people can discern that you are faking something.
Be honest answering every question, exaggeration is expected, outright lies and not acceptable and you will show some indication that you are lying or ducking a question.
You can’t do everything right, but you must try to do nothing wrong. Don’t give the interviewer a reason to turn off to you, once he or she tunes you out, the rest of the interview is perfunctory.
Lastly, watch body language to figure out when the interview is over and don’t try to prolong the session. If he or she is done, so are you, and he or she has already made a decision.
Just a few random thoughts….......