How to Make A Ball Jointed Doll
Prepare some rough sawdust in a bowl.
Put bonding agent on wire fingers, then put it in the bowl and dust fingers with sawdust.
After dried up, model details with sawdust mixed with stoneclay.
Cut arms at elbows.
Put joint balls which cut off the joint parts into shoulder holes.
Put joint balls into arm holes at the elbows then fix the details.
File all the parts with sandpapers, then put stoneclay all over, and make the surface smooth.
Check the balance of each parts.
Carve wrist holes and put joint balls with epoxy resin.
Cut the joint parts at the direction which other parts should be bend smoothly.
Also see How to assemble the ball jointed doll