A while back I made a handle for a dragon rasp. I recently made the second and took all of one construction photo.
The idea came from http://dans-woodshop.blogspot.com/2009/12/making-handles-for-new-tools.html. I used cherry from the stash. Like Dan said, saw around the shoulder, pare it down, shape the handle, drill, insert the tang, and tap the end of the handle to seat. I didn't do the burn-in treatment. I mainly used a small block plane to make the octagonal facets. Easy, fun, functional.
Also shown is one rasp taking a two day vinegar bath for sharpening. It helped. Except that rig soon fell over and dumped a pint of vinegar all over everywhere. The second time was the charm with a proper curved clamping fixture.