I don't really have employees to worry about; there is my partner, and myself.
I "slow moment" is an opportunity for my to clean my truck, sort through my parts, catch up on paperwork.
Then I turn to my cats. Yup, the four-legged kind. I take the latest pics around to my regular customers...just a friendly "hello." Quite often this turns into a general chat about what they're up to, and how I can join in. Or, my visit will give them a chance to bounce some ideas off me- things that were not so urgent that they didn't want to 'bother' me.
This is the time a regular customer really prooves his value. They will also have some little things they want done -things like changing lights, moving an outlet, little 'fixes' discovered in the course of other jobs- that they just haven't had the occasion to fix.
