I play a lot of local tournaments in Vegas throughout the year. I’m quite familiar with most of the tournament staff as well as the dealers. When I cash, I like to give them approximately 5%+ of my net profit, since I can’t tip the dealers individually as they share their tokes.
If I cash in a major event, such as the WSOP, they withhold a considerable amount of money for staff and other fees, and I generally tip a bit less than I would in a local tournament, depending on the amount.