Nervous energy

Showing that you are excited and energetic is good, yet nervous energy paints a whole different picture. Bouncing your leg, tapping your fingers or a pen, or shifting around is distracting and shows that you are unable to sit still, which is unprofessional. If you can’t sit through a 30-minute interview, how are you going to survive a two-hour meeting more importantly, an eight-hour day?

What to do: Take deep, steady breaths and pay attention to your breathing during the interview, make sure it hasn’t quickened, and keep it at a steady pace. Keep your portfolio on your lap to keep your legs from bouncing.
And keep the hand gestures to a minimum! My most prominent habit I need to break...

Posture

Bad posture during an interview can give the impression that you are lazy or disrespectful. Reclining might tell the interviewer that you are bored or cocky. Slouching forward gives the impression of nervousness. If you are constantly shifting from one position to another it shows that you are uncomfortable, this in turn can make the interviewer uncomfortable.

What to do relax against the back of your chair. Make sure your feet are firmly planted on the floor. Avoid sitting up too straight, as that can also make you look uncomfortable. It may sound crazy, but practice sitting at home and see how long you can hold a comfortable position without too much shifting around.