I always add a glued on handle to my billet bows. This way I can add some exotic wood with really interesting grain to enhance the bows look.
I leave 1" thickness in the handle area and glue another inch of wood to shape into the finished handle. I only use urac for gluing on handles and make sure I have a good fit on both pieces before I glue.
Here is an osage bow with an osage burl piece glued on ready for the leather. In this case I had less than a inch of billet wood to work with so I built up the handle area with two thin strips of osage that I feathered into the limb. The handle is less likely to pop off with the pieces feathered into the limb.
Another tip; if you glue on a rest, feather out the part that will be under the leather like the one in the picture so it won't show. I see a lot of big humps under the handle leather that serve no purpose, look ugly and don't need to be there.
One more thing and I will shut up; On this set of billets I was a little short on wood to make my typical bulbous handle. What you see on the handle in the middle is super glue and sawdust to build up the handle. One layer of super glue, a sprinkle of sawdust, more super glue, more sawdust etc. It hardens almost instantly and can be filed to any shape you want.
Finished.