Legs are on the right side of the mould, arms are on the left. I'll give more details about how I make the bones after the jump.
The bones originally start out as a piece of twisted foil, like this:
|The start of a humerus|
...and then I add more detail with paper pulp. When they're finished, they look like this:
|Two thigh bones|
I do the tibia and fibula together as one unit, and the same for the radius and ulna.
|Tibia and fibula on the left, radius and ulna on the right|
You'll notice I haven't yet had a stab at doing the hands and feet. I'm putting that off because as you can see, this is a really small skeleton and there are a lot of bones in hands and feet. I'm not looking forward to doing dozens of tiny little bones that will have to be maybe five millimeters long. Also, I have something slightly different in mind for this particular skeleton.