I agree pain is something I like, and to be punished in that way would be an ineffective thing.
I would think that a Master would have to look at punishments as a trial and error method. A punishment would have to be something the sub loathes, whether it would involve some sort of pain, or boring task, etc...
This is my own opinion, but even a punishment that is used often can eventually turn into something the sub starts to enjoy. So I would assume that punishments would have to be varied and more intense as time goes on.

I had a custom task created for me at the academy to get rid of bad habits I have formed over the years; seeing that I have a crabby, stubborn and defiant attitude, I was given a lot of punishments, that involved quite a bit of pain methods. Over time though the punishment became a more tolerable and enjoyable thing.
Silly me admitted that fact and the punishments had to become more difficult and painful. I was also made to do something I loathed completely and still do. So the one punishment, I will never enjoy became an effective method for doing what I supposed to do.