Sure, you have to look halfway decent in the way you dress, stay groomed and not stink like the chunk of two month old polish sausage that I just found hiding in the back of my refrigerator the other day... but the make-or-break factor is and always will be the WORDS that come out of your mouth, and the ATTITUDE that underlies it.
With that in mind, here's eight points to load into your mental backpack when you're getting ready to go off to battle.
Place her at ease with your laid back demeanor, and let her slowly begin to feed off of it. Be a lighthearted flirt.
Don't be obvious -- keep your interest vague so as to give everyone an "out" to protect all egos involved (both yours and hers).
She will appreciate your tactful approach immensely, and be impressed with your consideration and charm.
Sometime during the course of the evening, offer a single simple compliment about something unique to her style and presentation about herself.
No canned "You have such beautiful eyes..." compliments.
Don't go overboard or make a big deal about ANY compliments that you pay her. Make them seem casual and unplanned (a sudden pleasant thought that just popped into your head and slipped out before you could stop it...), then IMMEDIATELY move on to other topics. Trust me, she heard it. Touch Her To Seduce Her
Use any excuse you can dream up to get a hand on her.
Of course I mean only in the appropriate places... an arm, shoulder, a hair brush back.
Build chemistry dating within her.
Do not grope her like a desperate fool.
Touch is extremely important because it demonstrates a sexual, "manly" interest in her and keeps you away from the deadly "nice-guy-friend" category. Just make sure you always keep it classy.
Be A Man, Not A Boy
Keep your apartment styled in a mature fashion, avoid the frat-house look even though your football buddies will probably declare you a big puss.