I am a BCA member and normally have a decent game. Though at times I can run six racks and others not three balls. Through some reflection I believe the issue is with my aiming. I simply don't. When the stars align I shoot like god, but if i'm tired or preoccupied I am way off.
I have never taking a class or had instruction mostly as where I live there is no one I trust to be of help. So I would like to try an aiming system. I know that no one system is the be all of pool but lord help me there are SO MANY to choose from.
I would appreciate some opinions on which to choose if I am to choose one!
Let's assume for the moment that you are right, that it's an aiming problem. Focus is vital, but assume it's not that. Then it's likely that your head/eye alignment/height over the ball is off. The suggestions of Bob and Matt and others about preshot routine should help. Give special focus to head/eye alignment, tilt and height. A key check is if you can focus on the hit, on shots you are missing [but a good habit all the time]. Are you hitting where you are aiming? Even with no conscious aiming system, you must have something you use as reference to tell if the cue ball is going to where you intended. If you are hitting where you are 'aiming' when you miss, then we're confirming focus and an aiming problem.
You should also pay some attention to your eye patterns. Perhaps you are inconsistent and do a poor pattern on days you are distracted. Eye patterns have to do with where you look as you do warmup strokes and on the final shot. There are a few recommended variations.
And I hope you aren't jumping up or otherwise moving during or in the first second after the shot. Small changes here are disastrous for consistency.
I can suggest my aiming video (
https://www.youtube.com/watch?v=gCvaLS37FDo) as a way to give you some insights about the tradeoffs of the most common aiming systems. That theory as well as trying them out -- especially on shots that are their weak areas that I point out, should help you choose. I generally align when standing, based on my estimation of the ghost ball position, but I strongly agree with Matt that you need some exact aim point on the object ball for precision when you are down on the shot.
But I also firmly believe that learning aiming requires good fundamentals and the overall learning process involves both. And it's best to practice known shots with known aims. Inconsistency in that case means a mechanics problem. My AimRight product gives a good way to setup known shots and in the video I recommend a way to aim during that 'mechanics' training that aims at an exact spot on the OB, as Matt advises. If you want to evaluate an aiming system, I strongly recommend you test it out rigorously with a full range of cut angles and at various distances. People can be fooled by intermittent/short-term success that they've found something that will solve all their problems.
But what if it's not aiming? Certainly focus and preshot routines and mental attitude are critical. But I don't know if you are a pure shotmaker or play a strong all-around game. If you are a pure shotmaker, perhaps you need to learn better position play and/or pattern play to not have to frequently shoot difficult shots. If you play a strong all around game, then your failure to run many balls points to problems with fundamentals and maybe aiming.
One final thought. If you aren't 'into playing' because other things are important/distracting, maybe you shouldn't play that day. Playing then reinforces bad habits and just isn't fun. Or practice something different like learning a kick shot method or safety play. Something new will grab your attention in a way unlike 'regular play'. And if you must play (league, for example), try playing more conservatively, like much more safety play.