Dthomas pretty well has it covered. Dryfire as much as possible and focus on the fundamentals. Translate those fundamentals to live fire as often as possible even if you only have 300 yards to work with. If you want to work on wind calls inside 300 yards get a good .22lr.
I do disagree that shooting paper at 100 is ideal. A lot of PRS is spotting shots and making small corrections. Shooting small steel (1 moa) at 300-400 yards can build those skills pretty well while still focusing on the same stuff as shooting paper at 100 yards. I 100% agree with doing build and break drills as your primary practice regardless of how much time you have. Build a position quickly and break a good shot. Those are the basic skills employed in a PRS match. If you can do that and see where every shot goes and make good corrections, you will be well on your way.
If you have time, you should definitely shoot some groups at 100 yards on paper to check your fundamentals. Paper tells a story that steel doesn't unless you paint the steel before every string of fire.
Also, as was stated. Don't go to the range and try to set up and shoot a bunch of stages or props. Pick one specific thing you aren't very good at and drill 100-200 rounds on it, if you have the time and ammo. Once you feel comfortable with that, you can work on something else. If you try to work on everything with 5-10 shots per scenario, you don't really have enough reps to get better at any of them. You are just testing yourself, you are likely not really improving.
The more you can break the whole process into pieces and put in many reps at each small task, the easier it will be to put everything together and shoot clean stages. If you have a lot of time, money, and the drive to grind it out and do drills, you will do very well. If you just want to go to the range and smack some steel once in a while you will plateau quickly.
Some people have fun smacking steel. Some want to win. You just have to realize what you are up against if you want to win. The guys that are winning are working very hard and investing a shitload of time and money. Even if you are naturally talented, it is still going to take a significant commitment to get to the podium. If you are just out to have fun, practice might look different than if you are out to win.