Relax
If you've researched, prepared and practiced, it should be easy to relax. When you can do that, it'll be easy to demonstrate your commitment to helping the company succeed.

Be Confident
Sell your ability to perform the job in question. Don't expect the interviewer to ask why you're the right person for the job. Take the initiative and explain why you're the best fit for the position.

Provide Examples
When you answer questions, don't speak in vague generalities. Give your answer and include specific examples, including physical samples when appropriate. Remember, you're selling yourself and simply answering "yes" or "no" won't give the interviewer the "product" specifics that he or she wants.

Ask Questions
Asking questions shows that you've done your homework and have an interest in the company. It also allows you to learn more about the place you could be spending a great deal of time.