Mine is a combination of my first, middle, and last name. Maybe not an origional method, but I've found the handle to be very unique.
I actually started using it the name of an old email account, I think, anyhow, I've stuck with it for many many years. I've used a variant, smjraptor, (raptor as in velociraptor as I love dinosaurs and paleontology
) in a few places.