Have an objective in your interview.

I've talked a lot about preparation prior to your interviews, but what's the point of preparation if you don't know what you're preparing for. Do your company research before your interview and then decide what you want to accomplish in the interview.

Do you want to learn more about the day to day duties of the position? Do you want to learn what their competitive advantage is? Do you want to know what they're culture is like? All of these questions can be important but you need to determine these objectives before hand.

If you don't have an objective, you'll look lost and that will not get you hired, unless you're interviewing for Gilligan's Island.