Male: My favorite technique is to lie on the floor of the shower, lube up with some baby oil and aim the shower head right for my penis and balls. It feels great and provides an awesome orgasm.
I use one of those foamy 'cush' pillows. They stimulate me and I cum the most when I do that. Also, I do what you do.
I love the "stop'n'go" method. Just as you're getting to that point where you feel you're about to climax, you stop. Then, once you've cooled down a bit, you carry on going. It feels great and when you come it's amazing. Its like having lots of little orgasms and then a REALLY big one. I'm sure this is a common technique. Also, like I have repeatedly said, the bum-hole is a very good spot to stimulate as it makes the orgasm just that little bit better.