Say thank you to your interviewer at the end and after by email or send a 'thank you' card by post.
Analyse typical questions and write down your replies.
Do not go off topic. Keep your thoughts on the things you are good at.
Make it in time, to feel chilled and ready for your interview.
Interact, maybe, with the interviewer's twitter profile.
Advice for those looking for employment:
"Develop a contact network. Once you have targeted a career-path or specific position, you should get to know key players in that field or organisation. These professionals can offer you an industry insider’s view and can influence your contact network, which can open doors. Your business network can also consist of people such as family members, friends, professors, and those from electronic discussion groups."