Put in Q+A thread
It's Fthrow->Fthrow->DAir at the edge, has to be done at 0 though and you have to buffer the dair, when he comes up you just fair or upb him
In the center it's Fthrow (x2) or Fthrow -> FSmash, he can reach 4% before it stops working
Marth is a really annoying matchup, it's easy to punish dumb phantasms with dancing blade and fsmashes. If you powershield it's easy to block lasers which means that the Falco has to play really campy and has to punish well...and most Falcos (including me ) don't know how to do that. If you're at the ledge chances are the Falco will try to Phantasm or getup on shield, so just stay there lol. Even if they jump up from ledge you're free to set up traps (i.e. juggle traps)...basically the whole idea with Falco is just to aggressively zone with FAirs, DTilts, create ledge or juggle traps so that he eats tippers, and UpB whenever he gets close.
Learn reverse UpB too, Falcos sometimes will go through the shield and behind to prevent being punished for approach.