Working with an instructor who knows how to run a wheelgun is probably the best way to develop good DA revolver skills. However, that's not always feasible, so here are a few tips that work for me...
Pull the trigger straight through, no hesitation or stopping. Keep it as smooth and steady as possible until the gun fires. You also want to avoid going either too slow or too fast. The goal should be to pull the trigger quickly while maintaining a smooth and steady motion. If you have difficulty maintaining alignment, you're going to slow. If you're jerking the gun off target, you're going too fast. Trigger control is more important than sight alignment.
Follow-through is also important. Don't ignore the trigger return. Use the same principles as the trigger pull, just in reverse.
I've found it helps to grip the gun with the shooting hand using front-to-back pressure. I visualize my shooting hand as a C-clamp, with my middle, ring, and pinky finger across the frontstrap as one jaw and the heel of my palm across the backstrap as the other jaw, applying pressure. A hard grip also seems to make it easier to isolate my trigger finger's movement. If shooting two-handed, the support hand applies pressure side-to-side in similar fashion. With a two-handed grip, I apply the same amount of pressure: Maximum pressure until the gun and your hands start to shake, then back off until the shaking stops.
This front-to-back grip pressure also helps with pulling the trigger straight back. Using the crease of your index finger's distal joint will give you the best leverage, but the important thing is to apply pressure straight back. If you can keep the pressure moving rearward in a straight line, it doesn't really matter how much or how little finger you have on the trigger (within reason, of course). But it's generally easier if you can get the trigger face somewhere between the center of the pad and the distal joint.
LOTS of dry fire. Get some snap caps. Establish a safe practice area (i.e., safe backstop with no live ammo present), triple check your gun to make sure it's unloaded, load in the snap caps, and do some focused dry fire practice, i.e., all of the previously mentioned tips. Just cranking on the trigger isn't going to help much, other than possibly strengthening your trigger finger. 5-10 minutes a day should be plenty. Don't practice until you're physically and/or mentally exhausted. Being tired leads to bad form.
Speaking of hand strength, building up the strength of your hands can help, too. Stronger hands mean you can exert more force with less effort, i.e. you can apply more grip force without your hands shaking. I like Captains of Crush grippers.
When you get to the range and working on trigger and sights, performing ball-and-dummy drills can be a great help. It's best if you have a partner do this, but if you're solo it can still work. Basically, mix up live ammo and empty cases in the cylinder. Ideally you don't want to know which is which, which is why it's good to have a partner for this exercise. Otherwise, give the cylinder a spin before closing it properly (DO NOT FLICK THE CYLINDER CLOSED!) if you're alone.
This is what works for me. It may or may not work for you. Give it a try and see. Try the other members' suggestions. You should be able to find something that works for you and gives you the results you're looking for.
