I prefer a variation on the Rogers technique. I still hold the light between my weak hand index and middle fingers, but position it directly under the muzzle of the gun, such that the tailcap rests against the middle knuckle of my strong-hand middle finger. I find this makes it easier to activate the light than squeezing it into my palm, and I can keep the meat of my weak hand thumb against the frame of the gun for a stronger shooting grip.
This grip works best when the light has a prominent grip-ring. It can still be done on a smooth light, but it's a lot harder to keep a hold on the light.
I experimented a bit with the other grips, and had the same problems with all of them - They destroyed the two-handed stability of my normal grip, and I was no better off than shooting one-handed and holding the light completely separate from the gun. Maybe I was doing the others wrong, but the modified Rogers grip just works for me.