Do you tip everyone else you are paying to perform a service for you? Car mechanic, plumber when he comes over, etc? In most cases a golf instructor is a 1099 employee at a course, range, etc. if they aren't smart enough to set their rates at a decent level to live off of, they shouldn't be in business. Now if they go above and beyond what you paid them for, then compensating them for that is approriate. Some times my lessons will go over the alloted 60 minutes by 15-30 min, I make sure to compensate him for this. I think the tipping thing has gotten out of hand in a lot of areas. i.e. Starbucks with their tip cups, etc.