Okay, I don't know how much of this is just due to force of habit, and how much is due to being uncut, and how much is due to size, but -- since I can't reach all the way around mine at any point, I just do it with my thumb and fingertips, I don't grab and try to make a fist. And my right hand is up just below the glans. It's sensitive enough up there, especiall on the underside around the frenulum area, that long strokes aren't really needed.
What seems key for me is to keep some tension on one end or the other of the mobile shaft of skin. I either pull back the foreskin tightly enough that I get a tug at the frenulum from each downstroke, or else pull the foreskin up over my glans so that there's a tug at the base with each upstroke and the end of the glans is popping in and out of its cozy little home. Either way works just fine for me.
I also tend to to it with the angle of my cock pointed more away from my torso, so that the business end is at arm's length away, rather than pointing up.
I can get started in other positions -- like, reclined, making a fist around the base because it's still kind of exciting to feel how girthy it is down there, that'll get me started, but I'll always switch to working on the end long before I climax. I don't really think about it, there's no premeditation of technique strategies, that's just sort of how it works out.
I may or may not cradle the balls with my left hand, I dunno, if I do it's completely subconscious. My conscious brain is usually too preoccupied with a stimulating fantasy to be conscious of my masturbatory technique.
I can also come to a climax without any stroking at all, just by taking the lower "spout" of my foreskin between my thumb and index finger and gently roll it. This directly stimulates the frenulum, and when I do that I generate fairly massive amounts of cowper's fluid (precum). I can come very quickly that way, or by varying the intensity can stretch it out for quite some time, maybe losing and re-gaining my erection several times in the process.