My face once a week - I use a straight, so I can clearcut a week's growth in one pass without any trouble.
Forearms once a fortnight - I got tired of stuff catching the vellus hairs and yanking them out by the handful. Easier (and far less pain) to shave.
My chest weekly - hair comes in scraggly, I don't like the look of it, and I get tired of it getting caught in my bead chain (yeah, I still wear my dog tags whenever I leave the house. Along with a bunch of useful little stuff for EDC on the chain...)
Everything else? Let it grow!
(I can't use an electric on my face, beard's too tough and it just gets ripped out. I'd learned to shave with a straight, went away for a while for time's sake, and went back a few years ago because it costs FAR less than other razors!)
"recon" (sic - reckon)(tm) "hihgly"(tm) "seceed"(tm)
"Outback AIDS - Alcohol-Induced Dizzy Spells"