Be very very honest – if an interviewer senses at all you are being evasive in answering questions or are trying to fudge your way through questions, you're doomed.

Recognize that the interviewer is looking both at your knowledge and your thought process on how you would approach problems – for instance, if you get a “how would you build a 150 story skyscraper” question, just take a deep breath and start talking through how you would do it. Saying things like “it's impossible” shows lack of initiative and creativity and will negatively impact the interviewer's perception of you.

Don't lose your cool – the interviewer may intentionally be trying to get you off balance and see how easily they can frustrate you. Stay the course and don't allow the interviewer to get under your skin. Answer questions thoughtfully; not laced with emotion.

Show passion – interviewers will want to see how much excitement and energy you're going to bring to the job. Be passionate about the job, the company, and the products the company sells. Coming in with the excitement of cottage cheese will not leave the interviewer with a comfortable feel you are going to attack problems.

Be on time, dress nice, and smell good – These are very easy to control and can only help in the impression you make. Make sure your clothing is in-style, conservative, and fits you appropriately. Wearing a suit from the 80's that doesn't button around your midsection might not be the best attention-getter.

If you really want that job take a few minutes to get in the right frame of mind to put your best foot forward. If you're not going to put your best into it, don't waste the interviewer's or your time.