Be confident. Everyone likes someone who's confident. This is a very attractive quality for boys and girls! Of course, you don't have to actually be confident. Most people aren't, even if they seem like they are. Treat yourself well, don't constantly apologize to everyone, and get out there and do the things that make you you.
Wear nice clothes. Some great clothes will certainly capture attention. Wear clothes that fit the current fashions but also are flattering to your coloring and the shape of your body. You don't have to break the bank, either. Try resale or thrift shops in trendy areas or nearby colleges or universities for stylish clothes on the cheap.
Act like you don't care. Don't be clingy or desperate. This will make your crush think you have issues they really don't want to deal with. Instead, put on an air of cool. If they don't seem like they want to talk to you, go talk to someone else. Throw parties and don't invite them until the last minute. Show them that you have your own life and that your world doesn't revolve around cataloging every time they so much as sneeze.
Be easy-going and approachable. You don't want to intimidate your crush. Maybe they already like you but they're worried you'll blow them off or bite their head off if they try to talk to you or ask you out! Be friendly, don't over-react to things, and definitely don't act like a jerk if someone else that you don't like asks you out.
Let your crush see you with other guys/girls. Let them see you talking to and hanging out with other members of the gender you prefer to date. They need to see that you have other options and that you know you have other options. This will make you more desirable.
Talk to him or her! Of course, the best way to get their attention is to talk to them! They might not even know you exist if you're too shy, so get out there and have a conversation with them. Ask them about what they're doing this weekend, or how their day went. Ask them about things you're doing in school or their opinion on the latest football match. Anything that gets the two of you talking is great.
