I think everybody gave good advice.
This is what I do to stay in form. I believe the most important aspects of shooting are:
Posture
Grip
Trigger squeeze
Follow through

I practive with a air rifle in the back of my stand, a PCP with a 24X scope. You might laugh, but it works. The 24X scope over exagerate the movement of the rife on the target, after a lot of practice you manage to keep the rifle a lot more steady. A PCP air rifle has got no recoil, it is the perfect rifle to practice trigger squeeze and follow through. Firing a shot must never be a manual action. With enough training your brain will know when to give the command to squeze the trigger. Firing the shot is a brain function not a finger function. It is like changing gears, you do not think about it, it is automatically done when it should be done.

Oh yes and it is dirt cheap to practice with a air rifle.

Enjoy the practice