the simple answer is visualization. the longer answer is mentally running yourself through the stage and knowing exactly what you need to do so that you can play it in your head, with your eyes closed. you do this by mentally running through the stage plan repeatedly and it should help you fix any issues you may have with over running targets, skipping targets, forgetting to reload, etc.
think of a stage as a start and end point. between the start and the end you have to do a handful of things: shoot a target, move to a new spot, or reload. once you have a stage plan in mind, repeat the exact process in your head over and over from start to finish. if you get mixed up somewhere, repeat that part over and over until you remember it perfectly. It should end up looking like a queue system of things you need to do from start to finish: draw gun, look at a precise spot on each target, move to the next spot, precise spot on each target, move to the next spot, reload, precise spot on each target.