I bribe my groomer!
When I drop Jazzie off, I bring either some sweets or coffee. I figure they will appeciate it and most groomers I've known don't have time to eat.
When I pick-up Jazzie I usually tip about $10.00 - on a $45.00 bill.
Jazzie only goes to the goomer 2 or 3 times a year but they ALWAYS remember her when I call to make an appointment and they recgnoize her when I walk in.
This year I just bought a 100 holiday bow package (from PetEdge) to give her for an early Christmas present so she has 100 less bows to make.