I've been finding the Captain Falcon matchup particularly frustratingly lately (especially since everyone seems to have picked him up as a secondary). While any advice is welcome, I'd also like to know how to get around the n-air
Jab. Crouch cancel and jab. If it doesn't hit him directly out of it from the start, you'll ASDI "CC" the 1st hit even if it hits you out of a jab and still be able to jab again before the 2nd hit of the n-air comes out. Then either grab, d-tilt, f/u-air, or whatever while he's in a disadvantaged position. If you're at high damage you probably don't want to do it as much in case they happen to throw out a knee as you'll be less likely to DI it well.
On the character select screen hold full left and then full right. If the cursor stays level or drifts slightly down in a direction you will be able to do easy CC jabs and jab cancels while facing the opposite direction (the jab cancel isn't too useful for Ganon, but the CC jab is beast with him). Hold diagonally down and away and press the A button. If your controller is calibrated the right way you should be able to hold the direction and repeatedly jab over and over while staying crouched inbetween, and eat and counterattack any reasonably weak hits even if you're in the middle of jabbing. If you turn around and f-tilt your controller isn't well suited for it in that direction. You would have to CC, then release down on the control as you press A to do a jab in that case. If you can get used to it, it's much better to do your CCing by holding down and towards, as it won't really affect your DI if you happen to take a strong hit while doing so. When you go to jab switch to down/away if it works w/ your controller or release the control to do the jab otherwise, then quickly switch back to down/towards to be able to CC and re-jab if the jab gets stuffed.
If you do it right, you can shut down most of his air game pretty well. It takes some getting used to though, and if your controller doesn't jab cancel very well it's considerably more complicated. It mainly just leaves them DD grabs, which I find are best dealt with while facing forward anyway using SH u-airs/double airs, waveland f-tilts, jabs, f-tilts, and occasional d-tilts.
careful w/waiting for the shine to come out and then grabbing b/c lots of falco's are starting to multishine.
His shine lacks serious range and when he doesn't have the help of a dash's momentum pushing him ontop of them like the 1st often does it doesn't reach nearly as well if they jump into more, especially if the person holds away in shield during the first shine to get pushed further away. In Ganon's case they will always whiff if they hold away and try for a grab. Against most chars it's a near useless technique if they do this.