I've tried it all over the years, but my absolute favorite masturbation technique works like this:
1) Get 2 hot water bottles. These are made of soft rubber, and often red. You can find them at a drug store.
2) Fill them with warm water. It's nice if they are warmer than a woman, but not so warm that it burns.
3) Make a sandwich with the bottles. The easy and quick place is on the bathroom sink, since you can shoot into the sink and it's easy to wash up. But I also like to tie them down on the corner of my bed. They are a little slippery to tie, but if you can figure it out it's the best method since you really bang it without it moving around.
4) Place a dollop of K-Y jelly in the crack, and fuck away. If it gets too thick, add some water or spit.
5) Optional pleasure: tie your vibrator or electric toothbrush onto the bottles.
Have a great time!