I did not read all of the previous posts, so I might repeat some of the tips. I interview people on a daily basis. Here are few pointers:
- Research the company on the internet. You should know exactly what type of services the company provides and be able to articulate this to the interviewer.
- Be concise with your answers. Those who ramble are very annoying, and do not go very far in the interview process.
- Prepare answers that are commonly asked.
- If you were ever fired, do not divulge that info. It is illegal for your former employers to volunteer that info to a potential employer.
- BE ON TIME!
- Have a firm handshake. Limp handshakes are unappealing.
- Do not say anything negative about your former employers.
- Try not to discuss salary until at least the second or third interview. (This will depend on what type of position/role it is.)
- Dress professionally.
- Email or mail a "Thank You" letter after the interview. Emails are perfectly suitable nowadays.
Best wishes to you.