Wes,
To be perfectly honest I just make them all different. I turn the size down from the main dia till it looks about right.
Then use a file to shape the very end and a small round file or a rat tail file depending on the body size to blend the body to the end.
A lick with the old 400 grit emery to blend it all in and then brass polish on a rag to finish it. Since they are keyrings and are going to get abused in general life I figure it's not needed to go for the serious polished finish.
All that said, Form tooling would be a good topic to have in the tooling section
I'm sure there are plenty of people who will add to such a topic and plenty more that will happily learn from it.
You've made some cracking shapes up in the past..... Showing us exactly how it's done would be very good

Ralph.