Consider practicing with a .22 LR or .17 HMR.
Basic shooting technique is exactly the same whether you are firing a .22 caliber rimfire or a large caliber center-fire.
I suggest reading Army Field Manual 23-10, the most important part of this literature for you to read is Chapter 3 Marksmanship. It is sniper training literature. Even though you are not a sniper, like i said earlier the process of shooting accurately is the same with .22LR as it is a much larger rifle.
Using the tips provided in this manual. I produce groups smaller than a dime from 50 yards with a .17 HMR.