Unmanageable Hair, please Help!!! 10 points best answer!?

My hair is big, thick, frizzy, volumous, damged, wavy, and black. I'm trying to go for a more subtle look. I want to totally transfoirm my hair, but its so hard to do with my unmanageable hair. How do i make it thinner, less, frizzy, and under control? I've tried thinning it out and lots of product, but it only makes my hair greasy looking. I want to keep my wavy hair so no chemical processing either. Any suggestions? Any good hair styles and do's? please help!