A while back I asked my blacksmith what constituted a good client:
Someone with many horses and therefore much business?
Someone whose horses have difficult but expensive shoes? Easy but low-paying shoes?
Someone whose horses behave?
All my horses learn to stand for the blacksmith, load on trailers, ground-tie for grooming, etc. I was hoping this polite behavior was earning me extra points. If you have a good blacksmith, you want to keep him happy.
The answer:
“Their checks clear.”
Virtual Brush Box 
My blacksmith’s favorite swearing sequence was “the richer they are, the worse they are about paying bills on time. The poorer they are, the more conscientious.”
Note to self, next time I have a regular blacksmith, pay in cash, and have exact change. I want my blacksmith to love me.