If I'm at a new place I always show up with the intention of dropping $$. Between the HF and tip. Once I pay the HF and I know who my provider is or what she looks like, I then wait until they leave the room to let me undress, and I place the appropriate tip,based on her looks and potential for extras, next to the lotions and oils.
Once they know me, then I don't tip until the end. But I have to do it upfront at the beginning because I apparently look like LE