Resting your chin in your hand. You bored? Tired? Bored and tired? Wish you were somewhere else? No problem. The hiring manager will wish you were there, too.
Smiling too much (or not smiling at all). Yes, it's important to appear congenial and interested in the interviewer and in the job, but you don't want to come off like a con artist or a fake. Ask someone close to you if you tend to smile too much when you're nervous.
Bet you didn't know there were so many ways to be annoying! Before your next interview, practice with a trusted friend or adviser. Or videotape yourself answering questions. It could be the best thing you do for your job hunt.
Karen Burns is the author of the illustrated career advice book The Amazing Adventures of Working Girl: Real-Life Career Advice You Can Actually Use, recently released by Running Press. She blogs at www.karenburnsworkinggirl.com.