I use(d) manual stretching techniques whenever I masturbate. All I do is stretch the skin at the base of the shaft as far to or (now) over the tip as I can WITHOUT PAIN (should still feel sufficient tension, though).
I also started gripping lower on my shaft skin when I masturbate. This feels weird at first but you get used to it as the skin slowly stretches.
See that little discoloration toward s the top of your penis? That's all the nerve bundles etc. that were SUPPOSED to be internal at one point (but you were given no choice, right?) The trick is to get equal tension pulling from inside-out and outside-in. It's what's known as the P.O.E. (Point of Equillibrium).
It's taken me about a year now with the manual stretching. I'd recommend that if you were serious you might want to follow dbo4852's method (I've done that as well and it works pretty quickly.)
Just keep in mind that it's not an overnight thing, but the results are worth it, and that you are stretching CELLS. Skin cells become elongated when stretched and eventually return to their normal state. So inevitably you're going to lose some progress when you stop, which is why you wanna grow a "little extra."
Peace.
