If she was an easy target, you wouldn't be reading this. Therefore, she is not the type to be impressed by your money or your sheer manliness. You'd better make sure you have something else that interests her, or she may just be out of your league. You need some kind of hook. You can't appear to be too self-centered, OR too selfless.
Timing is everything.
Look for the signs that she's wishing someone would steal her - subtle complaining about her current boyfriend, staring off into space moodily, perhaps focusing on sappy music, etc. But DON'T act on these signs. Forget to answer email for a few days. It'll drive her nuts that she can't get male attention when she wants it, and she will be more receptive to you in the future. Having a deep, dark secret from your past is good, as long as it's nothing too weird, and preferably not your fault.