Minimum aperture - do you ever use f/22?

I use f/22 regularly when I test the sensor for dust: f/22, ISO that fits, shoot the blue sky or a white wall, door; need not be in focus at all and look for 'roundies' in the enlarged image: those are from sensor dust etc.

That is what f/22 is for, for nothing else, especially not for 'getting lots of DOF' on a lens extended to 18mm only as posted earlier; look up the DOF master and see where f/11 would get you on a wide angle lens! From your fingertips to the end of the world ....

Not enough? then close down to f/22 for the softening effects of diffraction in case you want a mushy picture. If that is your intent and style ..., more power to you!