I don't.

There is some keystroke I use that might accomplish quickly getting to the login screen.
I use KDE, you seem to prefer GNOME, so there might be some differences. If you can get the ear of Medo/Ahmad Samir, he seems to have a good idea of CL ways of managing the desktop, albeit I've only noticed his KDE magic.
Ctrl-Alt-BckSpc-BckSpc 'kills' the X-server, which might bring some extra not-so-good configuration but I use it quite a lot, usually when the desktop is frozen or really, really unresponsive because of some program or other going nuts.
Here, I have autologin and Ctrl-Alt-BckSpc-BckSpc restarts the desktop, bringing me to a brand-new KDE plasma, just like after re-boot, afaict.
On GF/nephew's computer, also KDE, Ctrl-Alt-BckSpc-BckSpc brings them to the login screen, as auto-login is not enabled. So, maybe this keystroke combination would do what you want, maybe not.

I think Ctrl-Alt-BckSpc-BckSpc is enabled by default, configurable in the X-server setup, iianm.