I've seen many indies (over 100) in the past 20 years (many repeats) and I always left a tip, even when I'm bringing a little something like a gift card. If it's their incall at a hotel, the $$ tip is always appreciated since they're spending the $$$ on a room. The only time I would not leave a tip if my research failed me and the provider was not as expected. In those cases, I thanked them for their time at the end of the session and left and of course, would never see them again. I've always found that little something (like a gift card) goes a long way. Now, I'm sure many of you may not agree; that's fine. Also, I usually do a 2-3 session, even on the first visit. I do my research and in all the years seeing independents, I've only been burned once. Back in the day I used to see agency ladies and those I always took care of since they have to share the fee with the house. Only used one agency (long gone) and I was never disappointed. I did have a direct line to the owner, so I knew whomever I chose or they asked me to see for the first time (call it a road test), I always left happy.
Unfortunately, those days are gone...