Kylek, wear something that is comfortable because if you don't look comfortable then people will pick up on that. Like if you don't like wool sweaters because they are itchy, then don't wear them.
You could also wear something that gives you confidence. If you know you look good in a button down shirt then wear it. Confidence will go a long way when it comes to attracting someone.
If you have a gay friend, sorry for the stereotypes but, have him help you pick something out. They have better fashion sense then I do and don't mind helping you out. I just wouldn't agree to let them watch you change.
Clothes that fit, Clothes that are clean, clothes that are well taken care of, clothes that compliment you..
I am a huge fan of Express though
I hate to tell you this, but you should really only "be yourself" The way you dress yourself isn't going to be universal unless you wear fancy designer clothes, but that attracts women cause their superficial.