Try not to go off on tangents. Keep your focus on your best qualities.
Define clearly your career goals and why you want this job.
Make good, first impressions - be polite with everyone you meet. Offer a firm handshake.
Breath deeply, relax your face muscles, take the time to pause before going in.
Dress for success. Dress stylish and precise.
Keep your language professional at all times.
Don't be afraid to admit you don't know the answer to a question. It's better than faking.
Job Hunting Tips:
"Before you begin to apply find information about the potential company. Understand what they do, their competition, and things that they feel are important. An employer won't take notice of your statements if you havent researched their operations."