The first flashlight technique I tried was holding the flashlight like a cigar between my first and second fingers of my support hand. The flashlight is pressed up under the trigger guard, while the support hand index finger goes in front of the trigger guard. I’ve seen this referred to as the Graham Technique. Except for that odd finger placement on the trigger guard, I found the technique very effective. The flashlight moved around a bit until I applied more pressure to pull it back into my hand on the pistol grip.
Next I tried the Harries Technique. In this, the flashlight is held in the support hand, which is crossed under the gun hand, and the back of your weak hand supports the gun hand. In dry fire practice, I thought this technique would be useful, but under live fire I found it woefully lacking in support and stability.
After devoting a few magazines to both techniques, I decided I would concentrate on the first technique, at least for this practice session. After a box of ammo downrange, I was pretty comfortable with holding the flashlight under the trigger and keeping it in place with repeated fire. Unfortunately, I can’t actually live fire in the dark with the flashlight. Any nighttime practice I get is limited to dry fire.
I finished up the practice with some close 5 yard precision shooting, which was surprisingly satisfying, followed by some 20 yards shots that were less so. In total, 150 rounds were put down range at this fun "lunch break."