Image 1 Caption: The runes of Gandalf and J.R.R. Tolkien (1892--1973).
A better version of the Gandalf rune is .
There is also a trademarked J. R. R. Tolkien monogram which is a pretty monogram made from his initials JRRT overlapped and stylized.
However, Tolkien initialed six of his illustrations for The Hobbit (1937, 2001) in various ways which I interpreted as approaches to a personal rune. The clearest rune is with the 1st illustration. My version is a variation on that.
Now yours truly thinks yours truly needs his own rune.
OK, that rune doesn't look so hot. But my symbol/seal is not so bad.
Image 2 Caption: David Jeffery symbol/seal.