Get enough sleep the night before your interview, you need to be able to focus on the task at hand, and you don't want to look and feel exhausted. Don't drill yourself and memorize everything you want to say, you need to be flexible in your answers and able to improvise. Relax and Have Fun. Don't let a case of the jitters sabotage your meeting. When you feel nervous, try to remember that the interviewer was in the same position once too. Also, remember that an interview is just a conversation so take a deep breath and make it a good conversation.
If asked to fill out an application, be neat and follow every instruction to the letter. Don't leave anything blank, write forthcoming in any space you may not have the information handy for. Don't ever lie on your application it could be grounds for not getting hired or getting dismissed at a later time.
Be positive about everything and everyone. Not fake positive, but not dumping on your boss for treating you unfairly, talking about how boring your present job is, or how stupidly your co-workers behave. Even an offhanded negative comment in the midst of a bunch of positive ones will stand out and concern the interviewer. They may be tempted to dig deeper into your comment and find a reason to take you out of the running. Or your attitude alone may do it. Besides, it's always a bad idea to burn bridges. You shape your professional reputation every time you come into contact with someone in your field. Even if it's for an interview that doesn't lead to a job.
Always elaborate on your points, never just give a yes or no answer, don't make the interviewer do all of the work.
Unless the interviewer brings them up first, avoid subjects like salary, benefits and the like because it makes you look like you're only interested in a paycheck, not in the job itself. At this point in your life the experience you will get is worth FAR MORE than an extra few thousand dollars. Also, it's in your best negotiating interests to wait until the last minute to discuss such items. Then you can know enough about the position to accurately rate its worth and how much value you bring to the position.
Remember an interview begins your potential employer receives your resume and cover letter and doesn't end when the interviewer closes their notebook and puts down their pen. Unguarded moments are often very telling ones. Nothing is off the record. Interview rooms tend to be small, go easy on the perfume or aftershave. If you have a meal before the interview stay away from garlic, spicy foods and alcohol. If you smoke try to change clothes before the interview (smoking in most business environments is frowned upon). No gum chewing. If a receptionist greets you, treat them as if they were the person hiring you. Be polite to everyone, the security guard, the elevator operator, the receptionist, and assistants. Hiring personnel often ask for feedback from other people in the company that you may have interacted with. Imagine what could happen if the person you are rude to in the hall is one of the people sitting across from you in the interview. You will be judged until the moment you are out of sight, the way you talk, act, and carry yourself. Make sure your car is clean and neat inside and out -- interviewers or their assistants have been known to walk you out to the parking lot, everything a interviewer may see should reflect the impression you would like to leave with the company.
Success is never final, and failure is never fatal. -Anonymous