You'd be surprised how simple a lot of answers really are when it comes to smash.
Such questions as "I am stuck on the ledge how do I get off?" There is no simple answer to that as you are in a bad spot to begin with. If your opponent is doing it right, you'll stay stuck there or dead. I think people already understand what their options are for example with Marth its wavedash, aerial from the ledge, standard ledge options (jump, attack, roll), etc. I assume people already know the options marth has from the ledge. What I think they want is a quick solution to how to get out of a bad spot and the answer is quite simply don't be in that spot to begin with.
So, when you ask for a visual cue its quiet true your ability to move your hands and response time to the ledge will be slightly different than someone else. A newbie has a hard time trying to short hop with fox which means they cannot release their finger off the jump button in 4 or 5 frames. Someone who clearly plays fox very well will have no problems with this. Now suppose you ask for a visual cue on when to release the jump button with fox... Yeah, uhh... it depends upon the person. The visual cue for the newbie will be slightly different for the more seasoned veteran. I suppose you could get someone else's visual cue, but that might not work for you. In the end, its best to work out your own.
To be honest, I do not try to look for visual cues for when to do something with my character. I want to try to avoid looking at my character as much as possible. It ends up being practice, practice, practice with mixing up your timings until you get one that works and you pick up the pace until it doesn't work, then let off.