Instead of wanting to know what a buncha guys do, don't you realy want to know what turns an MPA on/into happy time for you? Or, setting the bar lower, what you won't have her leaping up and calling you names? She's where you should be focussing, if you're into the NR version of massage.
Surprisingly IME, it's much the same as if you weren't paying: show some consideration for what she's feeling and give her a chance to adjust as the session builds. You can do it verbally, by touch alone, or combo of both. It is not an exact science, and there are no rules. But you are the customer, and to some degree you can count on her accepting/welcoming whatever version of things you try, as long as you don't crudely cross the limits, hers, the MP's or the 'industry's. Like any hobby, some of your first efforts are going to be clumsy, and may be disappointing. But count on it; it will get better.
That, or you'll find another hobby