This weekends GSSF match the scorer pointed out something very helpful. I've been gripping my Glock's poorly for years. I had spent a lot of time thinking it was my trigger press, pushing the gun to the right (I'm left handed).
To get a comfortable grip I was wrapping my fingers around the grip so the second knuckle would be forward and the gun digging into my thumb. The gun was not in line with my arm and pointed right when I pressed out. By putting the back strap of the gun in the big meaty part instead of digging into my thumb the gun is inline with my arm. Now just the pads of my fingers are on the front grip and trigger.
Unfortunately I've learned bad habits and this one may take a while to break. I did see a slight improvement in my targets.
Before:
After: