around here, the most common one (that I see anyways) is sixes and sevens.
FWIW, some states are getting away from letting John Q go rekey, and will begin requiring a locksmithing liscense to do so. Like a certain rectangle state with a rich little tail on the side. It's coming, wait for it.
I've been hearing rumors about that for a while.
The nationals will howl when that happens.
Professionals are people who can do their job when they don't feel like it.
Amateurs are people that can't do their job even when they do feel like it.