Yeah don't wear a lot makeup or tight clothes. Anyways, you should be flirty and nice to a guy you like! Check if he responds to your flirting. By the way, always make sure you are already friends with him! Walking up to a random guy and flirting is wierd. Anyways, always be nice, never snotty. And if you think you got him wanting for more, ask him out! Hope it helps!