http://www.mahoodsculpture.com/sculpture-tutorial/

I want to make my own action figure. What do I do?
I’d like to have an action figure of myself, but not sure if I want to pay to have one custom made. Plus, I like to be artistic. Besides skills in sculpture, does anyone know how I can make one myself. What materials do I need. Any online tutorials? Any suggestions are appreciated.
if you haven’t done figure modeling before you would need a lot of practice. It’s just like learning how to draw life-like portraits. It can help if you get some idea of basic anatomy and proportions. Be prepared that it will take quite a while, depending how accurate you want to the likeness to be.
A good material to start with because you can harden it at home would be polymer clay. there are also a number of books about figure modeling with polymer clay available. Just look at amazon com. You can check whether you can get some book at the your library first.
Sculpting a female head in clay. Sculpting tutorial and demo.