I can't say I've ever gotten a shave from a barber, but I've seen others who have.  I was in a shop once, and an obviously new barber nicked a customer several times while giving him a shave.

The new barber, in an effort to smooth things over asked solicitously, "Do you want your head wrapped in a hot towel?"

"No thanks." said the customer.  "I'll carry it home under my arm."