The sign for "San Francisco" as in "San San Francisco, California" is done by spelling an "S" and an "F".
(Model: Byron Cantrell)
Dr. Bill's notes:
You might notice a very slight forward movement as the "S" changes into an "F." This is not a conscious thing. It is just a natural aspect of activating the muscles to change the "S" handshape into an "F" handshape. If I were you I wouldn't "try" to do that micro forward movement, just focus on spelling "S" and "F" and you'll notice it happening naturally.
Notes: