Lots of practice. Also, make sure you've calmed yourself before the shot, otherwise, the aim may not stay true. Don't psych yourself out either. A lot of people get nervous around firearms. Don't be. I remember the first time I shot a gun (I was 7) and I was scared I'd mess up. After you get past the initial shock of the kick and the way the gun feels, it's a lot easier to focus, so make sure you're really familiar with your gun. Good luck!
Hunt coyotes. Learn about the coyote and hunting it. You get good at hunting coyotes you'll be good at hunting anything else. to bee a good shooter comes with putting rounds down range, the study of ballistics and reloading.
if being able to hit what your aiming at consistently with a rifle is what you hope to accomplish, here are some tips: 1-when shouldering the weapon make sure to place the buttstock on the meatiest part of the shoulder, 2-keep both eyes open during target acquisition and keep them open, 3-slow your breathing,4-wrap your finger firmly around the trigger and once you have positive target acquisition, slowly exhale while doing this firmly squeeze the trigger as if you were clenching your fist! It will require lots of practice to learn these techniques but once you do a marksman you will be!