Practice with lighter recoiling loads. I shoot lightly loaded .44s in my 629 95%+ of the time and shoot it better than just about any handgun I've ever owned, even when loaded to full-power.
Limit exposure to full-power ammo. 50 rounds of .44 Magnum at one sitting is ALOT of abuse and can really take a toll on you mentally, if not physically.
Dry-fire with the penny or dime trick. It helps. You won't batter your Smith dry-firing it, so don't be afraid of it.
Better grips. I find the N-frame fits me the best of any .44 revolver I've ever tried. My opinion is that the Smith is the smoothest shooting .44 I've ever fired, including Super Blackhawks and Redhawks. It's about fit more than anything. I'm going to actually be swapping my hard nylon grips out for a set of smooth wood ones after New Year's.
Practice with smaller guns. If you have revolvers in smaller, lighter calibers, shoot them more until you work the flinch back out. I only have the .44, so my option is to shoot lighter ammo, but the effect is the same.
And lastly, mental toughness. I do find firing my .44 to be kind of painful in places, especially now in the cold, over on the closely-confined covered firing point. But I just make up my mind I don't care, it won't hurt me (permanently) for half-a-box or so, and just focus on that front sight.
Oh yeah, sight picture and trigger control. Once those are taking up all of your attention, you kind of forget about the unpleasantness coming your way. At least, it works for me!