I'm no expert, but a lot of it is just studying and playing alot.
Learn your character's options in the neutral, how to bait, approach, and the like. Once you learn that, movement. Spacing works when you know not only your options, but your opponents options as well, and keeping space between you to anticipate those options. Take this video here and listen to what is being said on spacing
https://www.youtube.com/watch?v=RfBuAo_Bfvw
Edgeguarding can be broken down into several different options based on
1. Who you are edgeguarding
2 .The position they are recovering from
Say it's a Marth edgeguarding a Fox on FD, the most simple example. Fox can either upB or forwardB. if he does it above, then Marth can jump out and fair and interrupt, or wait to see the angle and dtilt/fsmash/throw them off. If at ledge level, sideB is the fastest option, so as Marth, I prepare for a dtilt or wd back (the ramen noodle). When recovering from below with upB, I can counter, Fsmash, dtilt, shield breaker, or ramen noodle.
If you know how your opponent uses their options as mentioned above, then edgeguarding becomes as simple as picking an option after seeing them start a move. You won't always get them 100% of the time, but if you look before you act, you can definitely increase that chance.
Being less predictable goes back to learning what your options are. Mixups can be as simple as choosing between a wd grab, and a wavedash dtilt for instance (still on Marth) in the neutral. Don't mix up to where you leave yourself vulnerable, like going on a platform above a Marth to drop through, as Marth can juggle you ( If you can't tell, I only know Marth the best lol )
Dont always go in, and try and keep your opponent guessing. You can dash past them and pivot grab, you can even run up and throw out a move, but you have to keep in mind your opponent's reactions, which is where conditioning helps.
Conditioning is using one option to the point where your opponent will expect it next time you set it up. You can mix someone up really bad like that, and then switching things up. If you have watched the documentary, this is like PC Chris's Hot Cold technique, where he will sometimes dash in and attack, and sometimes wait, punishing Ken's counters.
Message back if you need more help. By the way, I noticed you were from SA. Did you go to TGC? Will you go to any Houston events in the future? maybe we will see each other at one.
Good Luck!
