Two questions for both sides of the aisle here:
What types of compliments do you think your session partner likes to hear?
And what kind of compliments do you like to hear from your session partner?
I'm finding as I get older that I'm more prone to enjoying (and maybe, just a little) believing compliments of a non-sexual nature.
And, in turn, I'm finding that I'm focusing my compliments on various characteristics that I perceive in my lady friends-for-an-hour that don't relate to the physical activities we've engaged in. Of course, I don't think any woman tires of hearing that she's beautiful, but, after that, I start looking for personality, class, compassion, intelligence ...
One reason, I think, is that I'm projecting my feelings, rightly or wrongly, onto my companions.
Another is that I've had a few occasions when a lady has provided a window into some of the emotional issues that being a provider has brought her; in case they have similar feelings, I hope it helps, and, if not, then I think it's always nice to pay a compliment to someone when you can.
Basically, for the ladies, I think it boils down to whether, in the context of the hobby, you'd rather hear compliments you on how you do your job, or on the person that your client perceives you to be.
And for the guys, it's whether you'd rather hear what a stud you are, or that you're a nice guy (with the potential for an perceiving there to be an unspoken "but ..." as the next phrase.
Or do you really not give a care at all, so long as both parties to the transaction got what they, er, came for?