I've had a couple baseball bats around for a few years now, and have repurposed one to become the handle for a new 5/8" (or in British measurements, 1/2") bowl gouge. I really like the handle on the Hamlet skew, so I used that at a rough guide.
Instead of using a metal ferrule like I usually do, I decided to save a trip to the hardware store and use David Ellsworth's technique of wrapping the business end with cord.
I added a couple inches to the handle length as I often use this tool for roughing large blanks, and hoped the extra few inches will give me more leverage on those bumpy first cuts. It just fit on the lathe between centers. I mounted it with the business end on the headstock.
I used the lathe as a paint removal tool to see how the wood cut, and to make some guide marks for parting.
Here you can see the shape developing. I used a 1-1/4 rouging gouge for most of the cutting.
There's a little extra meat at the right end.
By offsetting the right side center 1/4 of an inch, I was able to turn about 6" of the handle oval. Well, more like a flat. I blended it in to the concentric section, and this gave me a more comfortable grip for the tool.
I drilled the bore hole for the shaft on the lathe, and super-glued the shaft in the handle's 2-1/4" hole. It took a few tries to get the cord wound (I'm no surgeon). Ellsworth recommends nylon cord, and mine kept snapping. My neighbor provided me with some cotton that seemed much better. I coated the cotton cord with shellac to keep things in place. We'll see how this holds up! Looks cool anyways...
I went easy on the sanding and finish, only going to 220, and using boiled linseed oil and a bit of carnuba wax. I prefer the grip of a lightly finished wood handle.