All depends on the situation. Agency girls appreciate tips a lot since they're not keeping the entire donation. Independents, all depends. Were you absolutely blown away by the service? Did you go overtime by 10-15 minutes and they didn't bat an eye? Are you planning on making them an ATF/visiting them regularly, or is it a one time thing?
No provider should expect a tip, but if you want them to rank you among their top clients and put in extra effort next time, a tip goes a long way.Do you put tip into the envelop in the beginning? And how much do you give? Is it 20%?
I've included a link to a prior discussion on this topic.
Im in agreement with the old thread.
Tip an agency provider.
If you wish to express appreciation, gift a self employed provider. She can always exchange or cash in the gift. After all how many Agent Provacateur push-ups does one girl need?
Once or twice I have bought good (pricey) take out like tapas to enjoy.
No. Not chips and beer
some tip up front, some at the end, some not at all
some in the envelope, some outside the envelope; some don't even believe in envelopes
some tip gift cards, some chocolates, some $20 bills, some $100 bills
some tip for exceptional service; some always tip; some never tip
... so it all depends on what your style is, my dear!! 
Zoey Zacquery has it right. It's always different.
I tip housekeepers, front desk employees who help me get the room I want, bellmen, street vendors, starbucks staff...I give to the homeless, too. It costs me very little to make someone else feel especially appreciated.
I believe in tipping.
I find it difficult to watch my date under tip a server and will usually sneak a little extra onto the table if I can without embarrassing my date. I don't understand bad tippers. Who (among hobbyists and providers) will miss a few extra dollars to make a tip or gift extra special?
I especially think a tip is in order for clients who need extra time arranging the session...whether they are trying to design the perfect role play, choose a hot outfit for me to wear, invite a third person to join us, or just enjoy extra communication pre-appointment.
My best tip was 1000$ for a 2H appointment. I've also received plenty of 100 $ tips and everything in between. It's a thrill every time, even when I get 20, 40, or 60. I feel happy for me, and I feel good about the tipper. If you want to be REMEMBERED as a generous tipper, 50$ is okay, but 100 is better. However, even throwing an extra 20 (you won't even miss it!) says, "Thanks" in a way that words just can't!
I had no idea! 50 bucks?
All depends on the situation. Agency girls appreciate tips a lot since they're not keeping the entire donation. Independents, all depends. Were you absolutely blown away by the service? Did you go overtime by 10-15 minutes and they didn't bat an eye? Are you planning on making them an ATF/visiting them regularly, or is it a one time thing?
No provider should expect a tip, but if you want them to rank you among their top clients and put in extra effort next time, a tip goes a long way.