I need a friend with benefits.?

I just got out of a bad relationship of almost 3 years and honestly, I just want to have with someone new. I'm 18 years old and I think I'm a pretty decent looking girl and I guess I just want to know how to approach someone that I want to sleep with. I just want a "friend with benefits" and I don't know how to go about asking one if my platonic friends about or even bringing up the subject with one of them.