You've had a string of bad relationships, or have never had a boyfriend. How on earth are you meant to attract "Mr. Right"?

[edit] Steps

Be yourself. No matter what, being yourself is the most important thing. If a guy doesn't like you the way you are, he isn't worth the time of day.
Dress well. This does not mean to wear a formal dress and strappy heels. It simply means don't dress like a tramp - you won't get "Mr. Right" that way.
Don't cake on the makeup. If you do that, he'll probably fall for your made-up face rather than your natural face. And guys don't normally fall for made-up faces anyway. Use a natural and feature-emphasizing color and a sheer gloss. (unless you look totally gross without it on; that won't attract anybody)
Be open-minded. That geek sitting next to you reading the 9000-page novel could turn out to be the guy of your dreams.
Lay down some rules for yourself, and set a time frame, eg: I will make friends with that cute guy that I like by next Friday.
Act on your rules. There's no point saying you'll do something and then putting it off ... and off ... and off.

[edit] Tips

Don't freak if a guy that you like doesn't like you back. Maybe you're not meant to be together.
If he doesn't like you, don't push and push and push to try to MAKE him like you; that'll make every thing worse and you'll end up wasting precious time finding the real right guy or having the real right guy find you.

Don't dress slutty. It doesn't do anything for you, and the guys that come up to you will probably want one thing: sex. Not a good idea.
Don't act like somebody that your not. If you find the right guy and he finds out later that you're a complete different person, that won't end up very well.