I usually tip $5 or $10. My regular masseuse does it like this, you buy four sessions and the fifth is free. So I tip her $5 per paid session and $20 on the free session, I guess that works out to an $8 tip on average. The sessions are 90 minutes and $75 each. She is fucking incredible though, just a great sense of what's going on in your body and how to make it feel better.