Suit. Dark suit!
Shirt, not too dark as you're not a gangster. Not white, you're not going to a funeral. Light blue is always good.
Tie. Not too skinny, not too fat. Not too loud!
Nice knot, skinny knots are ****e, half nelson i think its called that i use
Edit : the windsor http://www.tie-a-tie.net/windsor.html
