E.A.
"You don't always have to know the answer, but you do always have to know how to find out the answer."
My kids work for us first, so a lot of advice they get on the job. My oldest gets a lot of, "If I tell you to do it and I"m paying you for it, you DO IT." And my second oldest usually hears, "Leave the customers alone. Yes, I know they like to talk to you but they also want to eat their dinner, just clear the plates and let them be."
The rest is by example.