Most good players and pros aim basic cut shots by "feel" or "intuition" created from many years of successful practice and experience. Although, these people still have a pre-shot routine and a system of aiming even if they don't realize it or think about it. Most "feel" and "intuition" based "aiming systems" involve "just seeing the angle" and/or contact point visualization and/or ghost-ball visualization. For more info, see:One of the best players I've ever seen, Shannon Murphy from cinncinnati, said he pretty much just feels what he's doing.
Dave's Aiming Method (DAM)
How the Pro's Aim
Concerning practice, the best way to improve your "aiming system" is to practice any shot you miss. For example, if you are running racks of 8-ball, 9-ball, 10-ball, or 15-ball during solo practice, any time you miss a shot and/or position, retry the shot multiple times to see why you missed it and to make necessary corrections. This will improve your "aiming system" and hopefully make it more effective the next time you face similar shots.
You should most definitely think about and adjust for this stuff while planning a shot (unless you have enough years of successful practice and experience to the point where all of the adjustments occur totally naturally already). Regardless, you should definitely not be thinking about any of this stuff at all during an actual shot.I've watched most of Dr. Dave Billiards videos and they have given me an understanding of what is actually going on from a physics standpoint. I then try and see it for myself on the table and put it in my memory banks. I know about cut induced throw/spin, spin induced throw/spin, rail spin reversal, the limits of a miscue, and so on. But is it worth it to actually THINK about all that when playing? I feel like it's much better to let your subconscious do all that.
Even if you don't use a prescribed "aiming system," it can be useful to learn and try them out. Sometimes they might help you see things differently and/or better. They also help some people focus on actually aiming more and/or better. For more info, see:So basically at this point in my game would it be beneficial for me to look into an aiming system?
benefits of "aiming systems"
For more info on commonly discussed and used "aiming systems," see the aiming systems resource page.
Aiming systems can also be useful during play if a particular type of shot (e.g., a back cut) doesn't feel just right to you, or if you tend to miss it often. For example, when my "intuition" doesn't feel just right, I sometimes fall back on the following "aiming system:"
NV D.9 - How to Aim Pool Shots - from Vol-II of the Billiard University instructional DVD series
I hope that helps,
Dave