Get "inside" the table
JJacobson; What I do to get quality practice is, First I shoot a few banks to get the normal follow through stroke in gear, after about 5 mins. of that, I set the break shot up and try to start out by shooting the same cue ball for 25 pts., if you start with yellow always shoot it. I try from the beginning to make 25 pts. in 25 ings., then after the first game I try to make 25 in 20 ings., then 25 in 15, and finally 25 in 12 or 10 innings. This excersize will to teach you to pay attention to playing more position shots, instead of just trying to score the point in front of you.
Bill Smith "Mr3Cushion"
Jjacobson,
Hi. I actively teach 3c in NYC and help motivate many players to take on and enjoy the game. I suspect that you might have a more difficult time "trying" to make 25 points in 10 innings than Mr3Cushion could. Knowing your average is surely a good thing, but personally I would advise against getting overly fixated about it early on.
Here are some friendly suggestions that might help you to stay motivated:
DO become fixated on the subtle physical movements that are happening on the table. Whether a shot is missed or made, by you or by your opponent - like a hawk, pay attention to what the table does to the action of the cue ball, from the point it leaves the tip until it comes to a complete stop. You will find a lot of answers if you focus on things like: the stickiness of the rails and induced sidespin, squirt at different distances, how table friction wears away sidespin over time, how speed affects the shape of parabolic cue ball curves, and the final angle of the cue ball after it completes a curve (off of different ball hits or various rail reflection input angles). Actively take systems and shots apart, hunt for patterns, devise original systems, take notes, keep a log, a journal - however you like to study, study.
Try not to get discouraged by repeated misses. If you miss 100 innings in a row, train yourself to step up and shoot the 101st inning with 100% confidence. Learn as much as you can from your shots by establishing a useful pre-shot routine that provides you with verifiable ways to validate your hit, path, and ball-action. This gives you with the ability to create (an essential) "post-shot routine" that is driven with exacting feedback about the nature of the mistakes made, after the fact - be they conceptual or execution related. For example, being specific about where you intend to drive the first object ball, or pre-marking rail contact points, will allow you to diagnose problems regarding hit and speed in a much more serious manner.
Try to be "attentive" to each table's uniqueness by spending the time to read its personality - and continue working at developing a strong relationship with any table you are playing on until you walk away from it. Develop superman-level patience, because sometimes it could take as many as 20 innings (or more) before you begin to feel comfortable with a new table (or an old table on a new day!) enough to know whether the table will accept what you want to do with it - so that you may manipulate the balls as you wish. "Listen" to the table.
Unless you are clearly stringing together lots of long runs, trying to "play position" in 3-cushion prematurely could lead you to take shots using an approach that you are "not ready" for. It seems to me that the "correct" shot for a 2.5 avg player must be considered very different than the proper choice for a .4 player. It is difficult for a player to judge which is their best 2nd shot if they do not yet possess enough of a shot repertoire to see more than one reliable way of making most of the shots they get presented with. I have seen too many (initially) interested students turn away from the game prematurely because they somehow got driven to swallow too much, too early.
Whatever you do, try your best not to give up. 3-cushion just might be the most difficult game you may ever attempt to play, especially if you decide to measure your scoring rate shot for shot. But, if you measure success with joy, 3-cushion will give you many returns in the currency of satisfaction for many years. So, never give up - get used to "going back to square-one", dusting yourself off, reinventing yourself, keep trying, and you'll be a better player for it. I believe the average will take care of itself.
"Step inside" the billiard table. There is so much fascinating stuff going on in there - if you open up your senses, it can quite literally become impossible to get bored while practicing!
I hope this helps you.
-Ira