This is not what I do, but rather what I like having done, so it seems relevant here. Just before I cum I love having my scrotum tugged really hard. Before guys out there start cringing, I don't mean my balls but just the skin that surrounds them. Pulling my scotum away from my penis seems to increase the tension building and creates a more powerful orgasm. Not the easiest thing to explain to a woman, though. Many are afraid to pull too hard on anything down there...

my partnerpulls the skin back at the base of the penis it gives the head (I think) a little more resistance and when i cum it's explosive ~ Be prepared.