This one was tricky. (Hopefully, the writer likes it. She's off Wattpad until summer.) Anyway, the girl in the picture didn't have the right colored hair, so I used a layer on top of the picture, made it slightly opaque, then airbrushed away until it just covered her hair. I added the highlight in her eye and voila cool cover!
To check out this book look for IamChris70 's profile.
Just for giggles, I thought I'd include the original picture I worked from.