JusticeNJ,
As a couple of posters have already pointed out, keeping track of your performance is very valuable. First, it keeps you paying attention. Second, it puts pressure on you to do well, since you don't want to immortalize poor performance. The pressure to make those last two balls in a drill, or to complete it for the nth consecutive time to beat your previous record is much like the pressure on league night or in a tournament, so the practice is helping your mental toughness as well as your physical skills. It is important, though, to be honest with yourself and record everything you actually do. If you're going to lie to yourself you might as well quit now.
Another technique is to commit to doing a certain number of repetitions when you begin a drill, and stick to your commitment. It's especially useful to keep the number reasonable, and to do that same number every time you do that particular exercise to make it easy to compare your results over time. When you start to see improvement in black and white you'll probably find that you look forward to doing the practice much more than you used to.
You can also keep your practice interesting by adding variety. There's no need to do the same drill all the time. Mix it up. If you have more than one weakness, do drills for all of them (not all on the same day). Some guys like to practice on a schedule and do A & B on Monday, C & D on Tues, etc. Others just change it up as they go. One recommendation I would make is when you add a new drill, try to do it for 15 minutes or more every practice session for at least a week, preferably two. Then come back to it occasionally to keep your performance on that skill from dropping.
There are many ways to practice each particular skill you seek to improve, so you can do more than one drill or exercise to work it from more than one angle. But keep coming back to ones you've done before to both cement the skills you're learning into your brain, and to add to your database on your performance so you can see your trends.
There are a number of solitaire games you can play, like playing the ghost in 8, 9 or 10 ball, all offense, Fargo, Bowliards, etc. My take on these is that they are not as good as more formal drills in terms of how much you will learn for a given effort, but if you don't actually do them it doesn't matter how much you would have improved. Turning pool into work isn't going to be good for your soul.
