Elmer Keith, who was a short slim guy used to claim that short slim guys had less trouble with recoil than big heavy guys.

Here's some unproven suspicions:
Loosely held rifles will beat you up BAD
Trying to overpower the recoil with physical strength will shake up your insides BAD
Taking all the recoil with your shoulder will beat up your shoulder BAD
One way of holding the rifle appears to be to do a Charles Atlas like flexing of your upper body and arms while holding the rifle firmly against your shoulder pocket
If you can do the above while focusing on pushing your strength down through your feet into the ground, the felt recoli seems to be much less.
Having someone coach you by observing your stance and techniques is VERY HELPFUL (NEVER PICK A SPOUSE FOR THIS TASK!)
All suspicions, no proof