Before you even have a chance to say anything, a first impression blunder can cost you the job. Preparing for an interview requires hard work, from researching what the position requires to perfecting your response to the usual questions. One should typically be prepared to answer any type of question that the interviewer throws out. However, the interview is not only judged by what you say, but by how you say it and the manner in which you present yourself.

IN PICTURES: 7 Interview Don'ts

The Greeting

Job interviews will usually begin and end with a handshake, a subtle chance to give the desired first and last impression. Most importantly, make sure that your hands are not sweaty - expect the initial and concluding handshake and if you feel that your hands are moist, inconspicuously wipe them beforehand.

Deliver the handshake with confidence; one that is limp conveys uncertainty while one that is crushing would cause the interviewer discomfort. Your shake should be smooth, yet firm, and should not be overly enthusiastic. Furthermore, when shaking hands make sure you establish proper eye contact. (Big interview coming up? Check out Top Things To Know For An Investment Banking Interview for some tips.)

The Smile

The best way to approach the interview is to think of it as a regular formal conversation where non-verbal communication is just as important as what is said. Projecting a facial expression which is appropriate to the situation builds a sense of trust and allows the interviewers to have a better sense of what kind of person you are.

For example, simply smiling suggests that you are a happy person who will not complain about having to do long hours at the office. On the other hand, smiling for the entire duration of the interview could suggest a sense of fakeness. The best advice is to simply act like you are talking to a friend who is interested in your experiences since the last time you met.

Hand Movement

To establish a professional physical appearance, make sure that your hand gestures are appropriate and not overly exaggerated. Talking with your hands may be important in certain circumstances, but having them all over the place is not conducive to building your image as a professional.

If you are uncertain as to what the proper hand placement for the interview should be, whether they should be rested on the table or on your knees, simply mimic the position of the interviewer. Maintain proper posture.

The Look

Appropriate eye contact throughout the interview is another signal of confidence and professional demeanor. Find the balance between awkwardly staring at the interviewer and looking all over the place. While looking all over the room signals that you feel uncomfortable in social settings and may even suggest that you have something to hide, looking right into the interviewer's eyes for half an hour would make them feel uncomfortable.

Casually break your glance when appropriate for brief periods of time but make your actions appear unforced and natural. When interviewing in front of multiple individuals, shift your glance from person to person, as if you are talking to them individually, but give the most attention to the person who asked you the question.

The Conversation

Non-verbal communication allows the interviewer to make assumptions about your character; it is your job to make sure that those assumptions are positive. But there are other verbal means than what is explicitly said that determine the path of the interview. Voice volume and the use of the dreaded "umm" are two verbal cues which must be controlled. (Learn more in 7 Things You Should Say In An Interview.)

Saying "umm" too often shows poor preparation for the interview and lack of conviction in your answers, causing the interviewer to lose interest. Even if your answers are well thought out and intelligent, they will be drowned out by the "umms". Speaking too softly, like a weak handshake, suggests a lack of confidence, while speaking too loudly is unprofessional and unnecessary.

The Bottom Line

The manner in which you project your answers, verbally and non-verbally, has a strong impact on how the interviewer will view you. First impression blunders, such as an improper handshake, poor eye contact and inappropriate speech volume can easily be avoided through practice and a conscious awareness of one's behavior. Even if you have to think about your actions constantly, practice will help your behavior appear natural. (For more helpful tips, see Taking The Lead In The Interview Dance.)

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