I think Devil Dom really eloquently put everything I wanted to say and more.
I wanted to add a little to what he said. I think one of the most important things when playing with pain is the intent behind it. In other words, what do you want the sub and yourself to feel or what is the effect you want. This would really influence all three aspects that you mention quite a bit.
Personally I think you can never have too much of checking in or aftercare (although for plays like CNC this might not hold). What differs though is the kind of checking in or aftercare. I can elaborate with examples of needed.
I wanted to add a little to what he said. I think one of the most important things when playing with pain is the intent behind it. In other words, what do you want the sub and yourself to feel or what is the effect you want. This would really influence all three aspects that you mention quite a bit.
Personally I think you can never have too much of checking in or aftercare (although for plays like CNC this might not hold). What differs though is the kind of checking in or aftercare. I can elaborate with examples of needed.