I was trying to avoid a detailed technique description, because my words won’t do justice to what they teach. With that caveat, they start with a C clamp with the strong hand, strong hand finger tips loose, and maximal pressure set at contact in the holster (setting maximal pressure helps isolate the trigger and avoid sympathetic movement with ring and index finger). Support hand in quarter panel, then “nutcracker” tension from the base of both palms coming together, and finally the base of both hands wedging inward (their thought is power comes from base of the thumbs, not tips).
When we arrived at TPC, something my wife struggled with, was her split times increasing on shots five and six of a Bill drill. The reason is she was using muscle and not skeleton to control recoil, and recoil would eventually overpower her strength in an extended shot string. TPC completely fixed this, and on last run on the TPC 24, she shot a 15.67 hit factor test, indicating phenomenal recoil control. TPC uses your skeletal structure and not muscle to control recoil.
Enel, I shot a Walther Q5 during the course, and carried a P99. I broke the DP Pro on my Q5 number one and two pistols, and shot much of the course with an iron sighted Q5, which fortunately I had along.
I would have to try the grip sleeve, but I like the quarter panel technique combined with the other grip elements I described in paragraph one of this post.