I just made three handles for some new tools. Cost about $1 a piece. Green wood will shrink and crack. I suggest you find some nice dry hard wood for the handles. I picked up a bundle of 2x2" walnut cut offs at a local wood dealer for 10$..enough to make 20 handles.. any straight grained hardwood will work. For ferules I used copper tubing end caps -1" for the larger diameter bowl gouge and 3/4" caps for the smaller tools.

There are number of web sites with instructions. Google it.

Tom