There are a couple of ways I make socket handles. This is the forge intensive way. It involves a lot of hammer work, and you start with thicker stock.
One I made from an old file.
Another one from an old file.
The bushete and little one above were made from thin stock, required much less forging, and were fairly quick and easy to make. However, unless you pre-cut the material to a triangle shape, you end up with a socket that is like a tube and not tapered into a flare. This can be ok, but to make it fit the hand better, I wrapped a swell in it with some cotton cord, which I then saturated with shellac. Once that dried I covered it with the final wrap.
This is the socket on the smaller one.