I find holding drills to be helpful. Pope mentions it but in less detail than it warrants. Like he explains, position is important. It determines your Natural Point of Aim (NPOA). I use a "target" like the picture below and stand at a distance consistently the same and at NPOA, shoulder the rifle and hold the sight picture within a circle for a set period. The period is not the same as the period you would hold for a shot. It's a longer period of say 30 to 45 seconds. The object is to hold the sight picture within the circle for the full time period for all of the repetitions. When you can hold the sight picture through your reps without wandering outside the circle, you graduate to the next smaller circle.
What you are doing is training your coordination of the muscular/nervous system. It's surprising how quickly you can improve if you do this regularly.
This is not dry firing. You can incorporate it at the end of the repetition if you can do so without damaging the lock. Also, I don't consider it an alternative or substitute for dry firing.
View attachment 357523
I try that every now and then but without fail the RO calls me out for a safety violation.