At one time, when I shot pistols a lot more often, I would push forward with my right hand (the one I hold the pistol with) and apply rearward pressure with my left (support) hand. I find, these days, that I no longer do that automatically but if I remember to do it and make myself do it, it steadies the sights on the target.
Doesn't take a lot of rearward pressure/force, but a little will steady my sight pictures for the shot.