Lose the death grip. Gripping too tight can cause a reduction in accuracy, Pluff says. Instead of squeezing as hard as you can (which causes the muzzle to shake), establish a firm grip that doesn't strain the muscles in your arm and hand.
Work on your trigger control. As with a rifle, you'll need to practice your trigger squeeze so you get a nice, clean break. With a handgun's shorter barrel, problems with trigger control will be exacerbated, so spend plenty of time dry-firing, making sure your sights stay on target as the hammer drops.
Lower the power. Keeping your scope on a high magnification makes it difficult to find your target quickly. Instead, leave the optic at its lowest magnification.
Eliminate a flinch before it starts. Flinching is the result of physiological responses in anticipation of a shot, so you need to make practice as misery-free as possible. Wear hearing and eye protection and gloves, and avoid marathon shooting sessions.
Get planted. Accurate handgun shooting requires a steady rest in the field, so take along a bipod or tripod and learn to take advantage of natural rests.