Thank the interviewer(s) in person, by email or by post. Common courtesy and politeness goes far in interviewing.
Keep your language professional at all times.
Try not to go off on tangents. Keep your focus on your best qualities.
Don't speak negatively of former coworkers, employers or colleagues.
Remember the importance of body language such as eye contact, posture, active listening and nodding.
Set up a Google Alert about the company to keep informed.
Job Hunting Tips:
"Be sure to develop all the materials that you will need in filling out an employment application in advance. Even if you are supplying a CV, it is possible that you will also need to complete a standard application for the human resources department."