What kind of job is it?
If it is a restaurant job I have LOTS of specific tips of getting your foot inside the door.
In General:
*Smile!

*Lean slightly forward, that indicates interest.
*Always make good eye contact.
*If you're going to lie about something, believe your lies, otherwise s/he will see right through it!
*Show up a little early.
*MENTION YOUR GREEK AFFLIATION!
*Mention other orgainzation affliations, especially if it is service or professional oriented.
*Let him/her know in some way that you're a hard worker.
*Let him/her know in some way that you have good ethics, they look for integrity.
*Don't talk too much about your personal life!
*Shake hands firmly, but not too hard, a good handshake indicates confidence.
*Don't drink soda or chew gum before your interview.