Don't be afraid to admit you don't know the answer to a question. It's better than faking.
Thank the interviewer(s) in person, by email or by post. Common courtesy and politeness goes far in interviewing.
Be authentic, optimistic, focused, forthright and to the point.
Keep your language professional at all times.
Arrive on time, so you are relaxed and prepared for the interview.
Eat well on the day - no spicy foods!
Interact subtly on the company's social media - maybe like a post.
Job Hunting Tips:
"Develop all the info that you will need in filling out a job 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."