I typically use a brick bag with the grip's butt firmly embedded into the bag. That, along with a 2 handed grip and a straight back trigger pull gets the results I look for.
Slow and easy on the trigger pull. The Redhawk's trigger gun to gun is really quite variable I have found. The key to repeatability is single action mode...cocking the hammer for each shot.
I really have been amazed at the recoil on this large gun. It truly is not a pleasant gun to shoot compared to my model 29 that got ripped off.
It still is a darned good pistol though.