My normal game is $5 single-line VP, which makes tipping pretty straightforward - I do $10 on the straight flush, and $100 on the royal. Both of these combined probably happen 2-3 times a year.
But the other day I was playing .50 100-play, and after a few of hours of running hot, I had hit 10 handpays. I tipped on some, didn't tip on others (asked to be paid with a slot ticket), and in the end had tipped $100 total, which kind of seemed like a lot, in retrospect. If I expect to play this game regularly, that level of tipping would seriously cut into my EV.
I'm having trouble finding info on this anywhere else; can some of you VP whales chime in on what's expected/appropriate?