Just hit him with B air from ledge, forward or down smash the edge, or shine spike him if you are feeling particularly cheeky. Just holding ledge is also a very good option as I'm sure you know. If you know he's going on stage, you might be able to get up by wave landing or getting up normally and shred him from there because he probably just landed, full of lag, and is begging to be smacked by whatever you want to smack him with. Also the tech timing on Falcon's up b is the same pretty much every single time. Chances are you are either mashing or pressing L much to late.
Falcon can only watch with big salty tears welling in his eyes as he gets edge guarded by literally the entire cast, so the fact that you are having trouble with him means edge guarding and offstage play is a weak point for you. Not trying to be a meanie - do go ahead and get more comfortable with the edgueguard process, watch videos where high level foxes edge guard fastfallers and note the systematic approach they use to cover high and low options and how they are always watching for the tricksies that people employ. Specifically, Falcon can lean back to edge at the last second or end up behind you when you expected him somewhere else, so be cognizant of that.