An example of a very sweet "thank-you" note sent to me by a happy client after a session. Not at all a requirement, but nice when it happens.

Hello Mistress Matisse:
I don't usually e-mail a thank you but I just had to drop you a note and thank you for the wonderful session. You are such an artist that your moniker of Matisse is just perfect for you. Your palate of skills painted the most wonderful portrait for me yesterday; you combined just the right proportions of deviousness, mystery, pain, pleasure and sensuality.
The ball busting was fantastic (and still memorable as I found out when I woke up this morning). As you said, it is such a taboo, and that is part of what makes it so exciting, especially experiencing the taboo mutually with you. One can go online to Max Fisch and read about all types of ball busting experiences, and most of them seem to incorporate humiliation of the submissive. Now I know some people are into humiliation, (not my thing) but, really what kind of talent does a Dom have to possess to kick a guy in the balls and have him feel humiliated? Not much.
But to do ball busting and not make it humiliating, but make it a sensual experience as you did takes real talent. The way you would stop my balls from swinging then hold and caress them with your pointed boots and then kick them was fantastically sensual. The same can be said for the way you manipulated them and kicked them with your bare feet - not to mention that great slap sound you produced. You truly are the Nordstrom of Mistresses.
Thanks again and I hope to see you soon - I'm saving my pennies.
Remembering you fondly (especially my balls)

Of course, I did not literally "bust" his balls, in the sense of breaking or damaging them. I just kicked them - very carefully. Aficionados of ball-kicking are necessarily a brave group - it's an activity where, if you don't do it properly, you can injure someone in a not-fun, doctor-visit-requiring type of way. A Mistress's attention to the fine points is crucial.
This particular gentleman is rather tall, so rather than trying to pretend I'm one of the Radio City Rockettes, I had him get on all fours on the floor, knees splayed wide. He watched me in a mirror as I stood behind him and took precise aim at his dangling, vulnerable flesh. There was no bondage involved - he stayed in position because he trusted me and he wanted to be there. Sometimes after a particularly resounding smack of my foot on his ball-sack, we'd both say, "Oooooo, good one!".
I really like what I do.