Captain crush grip strengtheners are awesome. I'm up to 195 lbs for 1 rep. I don't really hold a gun super hard though, especially when I'm going for accuracy. A lot of the time when I shoot at 25 yards I just let the gun sit in my hands and let it recoil as much as it wants. With good technique the gun recoils straight up and settles back on the exact same spot. No need to grip like hell unless you're going for fast split times. Or if you're shooting something silly like .460 mag.
I really try to think of pulling my finger back and touching my nose. I get the idea of the trigger mechanism out of my head and just move ONLY my index finger and usually I'm surprised by the recoil, which is what you want.