Don't go over the top

If you put a lot of make up and wear the slutiest, tiniest outfit ever, you will send out the wrong message, and attract all the wrong guys; no classy, respectful guy would approach someone like that.
I recomend you mentioned him that you love guys that wear... whatever you like (I love suits) when you two see a guy wearing that; and immediatly ask him what he likes women to wear. Get whatever he mentiones, and wear it the next time you see him; remember to playfully point out that you're wearing what he said, and if he likes you, he'll have the opportunity to let you know by wearing what you said!