I did this a little while ago when I was trying to get back in to drawing! It's probably around 3 months old, now. I didn't ever do anything with it, so I figured I'd upload it for others to use. <3
All of the files are on a transparent background (or should be!) so you should be fine using it.
This is a .psd file, so you'll be able to open it in a lot of programs.
My only rule is to give credit where credit is due! I'd also love to see whatever you do with it.
I'm also quite happy for you to trace the base if you want to use it with a different hair style/expression. Changing the hue of the hair/eyes/skin is fine too. Pretty much anything goes. Again, please credit me for it.