Research the market, directors, and job opportunity.
Thank the interviewer(s) in person, by email or by post. Common courtesy and politeness goes far in interviewing.
Be authentic, cheery, positive, direct and concise.
Don't be afraid to admit you don't know the answer to a question. It's better than faking.
Ensure that your latest twitter and linkedin messages are positive.
Don't brag too much. Humility is persuasive.
Job Hunting Tips:
"After you've selected a calling or occupation, speak with leading voices in the area. A network should also punctured with school friends, lecturers, and those from forums."