Go to the range and shoot. There are no substitutes. And not off bags. Shooting freehand standing will make you a better shot weather you hunt that way or not.
I hate shooting ranges. Ive been to a few and I'd rather stay away frim the idiots. My advice is go squirrel hunting and only take head shots and dont use a rest. Dont let moving or running ones get away. Shoot them in the head. If you can go out and get 10+ squirrels multiple times then you are ready to start hitting deer.
