You can put on a real show about it if you're able to pull it off and it does work amazingly well for some guys. But if you're more laid-back, start talking to her in general and have a natural conversation. "Hey, what's going on? Nice day isn't it?" If she gives you the hair flip and the narrowed eyes, forget about it. But if it seems like the chit-chat is flowing smoothly, wait till she is smiling or warming up to you. Read the face and body language. Then take a breath, look into her eyes and tell her something like this: "You know what? I really like you. Would you go to the prom with me?"