I was hired recently to build a custom cane for a pretty tall man. He needed one that was a few inches taller than he was able to find, and he did not like the cheap adjustable ones. However, he wanted to reuse the handle on his current cane, which was too short, but he liked the feel of the handle. So I suggested to him using cocobolo for the cane shaft, with a 1 1/2" section of ebony on the top end before it joins the handle, which would balance with the rubber tip on the bottom end.
In order to attach the ebony to the cocobolo, I basically made a mortise and tenon joint on the ends. The shaft diameters were 1" and on the end of the ebony, I used my table saw and miter gauge to slowly spin the end into the blade, like a lathe, taking the last 3/4" length down to 3/4" diameter. Using a sharp chisel, I then cut 6 sides into the tenon I'd just made.
I made a simple drilling jig to bore a hole into the end of the cocobolo for a mortise, and used a narrow chisel to cut corresponding sides into the mortise. It ended up being a 5/8" diameter, 6 sided tenon, and fit just snug. I then incised some notches into the sides of the mortise, and in corresponding places on the tenon. I used G-Flex epoxy to glue them together. I then drilled out the pilot hole to attach the handle, as it screws onto the shaft, and bored deeper, all the way through the ebony and into the cocobolo. I inserted a strong screw down in, securing the ebony to the cocobolo, then attached the handle. Sanded to 1000 grit and applied 4 or 5 coats of oil to it.
My customer was, and remains, delighted with it.