I was always a good girl with my Master (I just couldn't not be and we joked about this a lot) but what he finally did was very earnestly look me in the eye and ask me if I was willing to take a bit of pain for him...
I of course saw this as a way to prove myself to him and he saw it as a sign of my loyalty and devotion. I liked this way because it was so intimate and wonderful. I think I would have a problem with being 'punished' if I had done nothing wrong.