To me, it's all about the circumstances- e.g. depends on the vibes I'm getting and what is my realistic expectations on any given visit. Yes, I have been a cheapskate before: I went to a known R&T bought the 1/2 hour and after 25 minutes of rubbing with teasing- she said "DUHN" and when I asked for flip? she said 1/2 hour doesn't cover front side. Then went and waited with water for tip at front door. Protested when I left nothing- but I mentioned that I was not informed 1/2 hour was not "full body"
Other times, I go in with an expectation of legit and that's what it is, but if I feel good about it I go for the 20. If I got mixed signals like there was more and then was shut down and the rub wasn't good, I will tip less than standard(usually like 10) to voice my displeasure of being teased to blue balls and left dangling
Another circumstance: couple weeks ago I visited a Northside AMP what I considered was a legit place.
Stopped in there 1 other time over a year ago and got nothing. Tried again, and on the flip the average looking thicker Chinese gal with my guidance started the HJ. I was going for NE, but only seemed to be OTC. When I left I felt guilty that I had only planned on the 20, so I made it 25..the 1/2 hour was only 35 anyways. A steal for what I thought was a legit place with no play.
Just my $0.02