Aiming doesn't have to be complicated, especially if you can visualize the object ball contact point and estimate the location of the cue ball contact point. If you can do that then all you have to do is point one at the other.
Accurately visualizing the OBCP and estimating the CBCP takes practice and memorization, and having something to "measure" for each cut angle makes memorizing them much easier. Here's the way I do it:
For each shot I simply notice how far the tip of my cue is pointed away from the OBCP. For thinner cuts this distance is larger (like in the first picture below); for thicker cuts it's smaller (like in the 2nd and 3rd pictures below). I don't do anything special with the information - simply taking notice of how much it is for each shot helps me memorize cuts quickly and repeatably.
View attachment 176662
This isn't a system in the sense that elaborate methods like x-angle systems are, but "systematically" focusing on exactly where my stick is pointed also helps me get aligned consistently with each shot, which I think is very important.
This is similar to ghost ball, since my stick points to the ghost ball center by definition, but I don't visualize a ghost ball. I try to visualize the CB contact point aimed at the OB contact point, and so I think of this as contact point-to-contact point aiming.
Of course, aiming adjustments must be made for squirve caused by sidespin. Noticing the
adjusted "offset distance" is also helpful for memorizing cuts with sidespin.
pj <- that'll be $40 please
chgo