These are fun to make. I use a 1" forstner bit to drill 1/4 on the end, and then clean up the drill marks with a scraper. After that, just shape as you see fit.
From Left: cherry & purpleheart, juniper, spalted purpleheart & aluminium can, cocobolo, walnut, redheart
All except the cherry are a CA finish. The cherry is beewax. It just felt right.
I'm pretty sure this design is what got me into the gallery I currently sell bottle stoppers at.