Crossword puzzle constructors do it until they cwm.
TeXnicians do it in horizontal mode.
Free Software developers do it where everyone can see.
Lawyers do it sua sponte.
IC designers do it with masks.
Moderators do it in the correct forum.
Stagehands do it in the dark.
Runners time themselves while doing it.
Emacs users do it with all kinds of strange bindings.
vi users do it with both hands on the home row.
ed users even do it on very small systems.
Eventers do it 3 days, 3 ways
Technical illustrators do it both vector and raster.
Technical writers do it according to the style guide.
Electronics techs do it on the bench.
Cyclists do it on two wheels.
Cartoonists do it on paper.
OK. If you made that one up, you’re good.
Musicians just practice their fingering
Hockey players do it on skates.
Back in my Air Force days we’d say…
Crypto techs do it in sync.
Electricians do it until it Hz.
Secret agents do it covertly.
Monks do it out of habit.
Programmers do it top-down and bottom-up.
Database adminstrators log each time they do it.
Jugglers do it til they drop 
I thought that musicians duet?
Geologists do it in beds.
Botanists do it in the plants.
Geologists do it while getting their rocks off.
Talors do it in their pants.