REHEARSE. It's the single most important thing you can do. The best way to do it is with a friend taking the part of the interviewer. It doesn't matter if the friend is exactly like a real interviewer, it's the question-and-answer dynamic that's important. The idea is NOT to develop a slick, scripted presentation. The idea is to get used to surprises, so that you can continue to FUNCTION even when you are feeling little stressed, awkward, or off balance. I was laid off at a big company in the 1990s. The HR rep said "If there's anything I can do to help, let me know." I looked her in the eye and said "Do you really mean that?" She said "Yes." I said "Well, could I get my camcorder and come to your office, and could you give me a pretend job interview while I tape us?" She agreed. It was one of the best things I ever did.

Watch these wonderful videos. I'm sure it'll help. http://www.youtube.com/watch?v=Qhz9dz9lle8

Try to relax in the interview , also rehearse in front of the mirror.