It's a not a game of charades, it's a job interview. Here's what to do (and not do): Don't:
Rub the back of your head or neck. Even if you really do just have a cramp in your neck, these gestures make you look disinterested.
Rub or touch your nose. This suggests that you're not being completely honest, and it's gross.
Sit with your armed folded across your chest. You'll appear unfriendly and disengaged.
Cross your legs and idly shake one over the other. It's distracting and shows how uncomfortable you are.
Lean your body towards the door. You'll appear ready to make a mad dash for the door.
Slouch back in your seat. This will make you appear disinterested and unprepared.
Stare back blankly. This is a look people naturally adapt when they are trying to distance themselves. Do:
Sit up straight, and lean slightly forward in your chair. In addition to projecting interest and engagement in the interaction, aligning your body's position to that of the interviewer's shows admiration and agreement.
Show your enthusiasm by keeping an interested expression. Nod and make positive gestures in moderation to avoid looking like a bobblehead.
Establish a comfortable amount of personal space between you and the interviewer. Invading personal space (anything more than 20 inches) could make the interviewer feel uncomfortable and take the focus away from your conversation.
Limit your application of colognes and perfumes. Invading aromas can arouse allergies. Being the candidate that gave the interviewer a headache isn't going to do anything in your favor.
If you have more than one person interviewing you at once, make sure you briefly address both people with your gaze (without looking like a tennis spectator) and return your attention to the person who has asked you a question.
Interruptions can happen. If they do, refrain from staring at your interviewer while they address their immediate business and motion your willingness to leave if they need privacy.
Stand up and smile even if you are on a phone interview. Standing increases your level of alertness and allows you to become more engaged in the conversation. Say Goodbye Gracefully After a few well-thought-out questions and answers with your interviewer, it's almost over, but don't lose your cool just yet. Make sure your goodbye handshake is just as confident now as it was going in. Keep that going while you walk through the office building, into the elevator and onto the street. Once safely in your car, a cab or some other measurable safe distance from the scene of your interview, it's safe to let go. You may have aced it, but the last thing you want is some elaborate end-zone dance type of routine killing all your hard work at the last moment.