Don't arrive too early. Make sure you respect your interviewers schedule
Answer questions with a simple 'yes' or 'no'. Use the CAR Technique (Context, Action, Result) wherever possible. Share things about yourself relating to the position.
Lie. Always answer questions truthfully, frankly and as concisely as possible.
Ever make derogatory remarks about your present or former employers, colleagues or companies.
'Over-answer' questions. The interviewer may steer the conversation into politics or economics. It is best to answer the questions honestly, saying no more than is necessary.
Let your discouragement show. If you get the impression the interview is not going well and you have already been rejected, don't show discouragement or alarm. Occasionally an interviewer who is genuinely interested in you may seem to discourage you in order to test your reaction.
Ask about salary, bonuses or holidays at the first interview - unless you are positive the employer is interested in hiring you and raises the issue first. However, know your market value and be prepared to specify your required salary or range.