Here is how i learnt how to aim in cuesports
Line up a shot, attempt to pot it. Depending on where the object ball goes, you know you hit it too thin or too thick. Set it up, make the necessary adjustment and try again. Once you have the shot down, repeat until memorised. Rinse and repeat a few hundred thousand times with all different shots.
Now i play both snooker and pool and i'm not one of these 'snooker elitists" who think snooker is way harder than pool. Both games are hard in their own right, the speciality shots in pool are very challenging to learn.
However you can't dispute that just isolating the potting, snooker is harder in that regard. Not just the bigger distance, the cut on the pockets and size of them makes all the difference.
Now you go to any top snooker forum, e.g. check out
http://www.thesnookerforum.com/board/forumdisplay.php?f=11
and there is virtually no talk about aiming or aiming systems. It's all about cueing technique to produce a ramrod straight, repeatable stroke. Every aspect of stroke mechanics is discussed on snooker forums.
But here on a pool form where the potting is exponentially easier, it's all talk about aiming systems (quite passionate heated debate like we are talking religion and politiics) and not anywhere near as much talk about stroke mechanics. I definitely don't agree with this 'your find your natural stroke' stuff. The human body wasn't made to use a cue to hit a ball, there is nothing natural about it, watch the top players, every single friggin detail and learn from them. The players who have even attempted to deviate from standard recognised perfect cueing in snooker (e.g. Tony Drago and Joe Swail) have been journeymen at best, only having the success they have due to enormous talent, every single No 1 player in snooker history has had perfect cueing technique (John Higgins, Ronnie o sullivan, Stephen Hendry, Steve Davis)
Anyway it's just an interesting observation from someone who enjoys both the pool and snooker worlds.