I find I have better accuracy with my Colt series 80 1911 45ACP in a two-hand stance with my left foot forward (I'm right-handed).
I concentrate on lining the rear sight up with the front sight, concentrate on where the front sight is pointing, then squeeze the trigger with the "meat" of the last segment of my index finger (NOT the crook between first and second segments nor the "tip" of my finger).
230 grain cast lead round nose in the original GI profile with anywhere from 3.6-4.5 grains Hodgdon Clays and a LPP sets me sailing for a fine afternoon.
The four steps include:
1. Sight Alignment. This may very a little where to put the aligned sights on target
2. Breath Control. Breathing while shooting does move the firearm so slightly, but it still moves.
3. Trigger movement. Some say squeeze, others say mash. Be smooth with the movement required to actuate the releasing of the sear.
4. Follow through. This is the step that most don't understand. Basically, keep holding the trigger until the firearm settles down and you get back on target. Then release the trigger. Snapping the finger off the trigger when it shoots can move the firearm enough to miss. Try it when dry-firing. Release the trigger slowly one time, then as you normally release the trigger when on the range the next. Which keeps the sights lined up? (put a nickel on the gun for more pronounced action).
I have to say practising with a coin on the top of my P64 is not going as well as I would like: after 10 shots it will walk out. You can see after I pressed the trigger and the hammer smacked the pin it will shake a bit. Would it be the hammer impact shaking it or user error (holding the gun too tight, releasing trigger too soon, or whatever)?
If the coin drops off each time, there are multiple problems.
To keep it on for a couple of dry fires is doing correctly.
Now, use the same trigger movement on a blank piece of paper at 15 yards. Aim for the middle and see where most POI end up.
Why blank? Then you can concentrate on the front sight without the distraction of aligning on the bull's eye. You are shooting at the "center of mass" on the target.
If most hits are not in the center, then sights need to be looked at.
It does not drop with every shot, but if I center a penny just behind the front guard, after 7 dry fires it will work its way to the right of the slide and fall off. i.e. slightly better than falling at every shot. And, yes, I am using the light weight (18lb) trigger spring.
Note I shoot the P64 single hand -- left -- if that matters.
Now, for the blank paper exercise, the aim is to see how the sights get misaligned after each pull of the trigger?