When it comes to practicing position play, one school of thought is to practice specific sets of positional shots. When I first learned how to play pool, I used a system called Target Pool, which literally gave me a big target to land the cue ball on, and gave drills for practicing different elements of speed, draw, and follow. You can do the same thing for yourself using napkins, note card, or sticky notes.
The idea for you should be to select a group of shots that you come across frequently in regular games, and then figure out what positions on the table you might want to get to from each shot. At the beginning, try thinking of at least 3 positions involving draw, center, and follow, and then later add in longer and shorter positions with draw, center, follow. Each shot will require you to land the cue ball on the target napkin. Take notes, make some short lists. This way you can keep track of what you are doing.
Billiard Balls
Now when you begin practicing these positions give yourself a target # of successful attempts, maybe its 3 successes, maybe its 10 successes. Don't move on to the next shot until you make your target # goal. By practicing the same shots and positions repetitively, you ingrain success into your muscle-memory, and your brain become familiar with your choices so you don't agonize quite so much over what to do when you're in a real game.
It is this kind of repetition that will help you learn how to play pool. You will become more consistent with position, and be more prepared under many circumstances. Just playing through a rack of balls might challenge you to get creative in order to find position on the next ball, but until you have a portfolio of familiar shots already under your belt, you will still struggle. So build up your portfolio of shots you are comfortable with, sharpen those weapons through repetition, and then you'll find things will become a lot clearer come game time.
How to Play Pool - Target Practice