ugh, Kevin stop asking non-Samus mains for advice on the Samus match-up. You may learn how to beat 95% of Sami with that stuff, but the other 5% will obliterate you.
First off. You can't just camp Samus. Especially not as Falco. You have *** mobility, and eventually you'll have to challenge her positioning. This is misconception number one about Samus. The truth is, the best Sami don't afraid of your projectiles. If you try to kite Samus, she'll pressure you until you leave the stage, then she'll edgeguard you. Rather than do something that gets stale easily like, "playing like a *****," mix up retreating lasers, bair camping, and approaches with a variety of options.
Misconception number two is that you can bait Screw Attack by shielding.
Well, okay you can. That's one option, but then that just lets Samus mix you up. WD oos into jab shenanigans, and Falco is trapped in shield. If you had solid mobility, you could bait with DDing, but has much less margin for error with Falco.
Ultimately, you have to spend a lot of time trying to figure out how the Samus is going to respond to your jump-ins. At the same time, you don't want to show off all your tricks for baiting her responses, because then she'll know how much you know right off the bat, and it'll all be over.
Options Samus has against you on-stage:
Jab: This move won't really be used if you're on the offense, but once you're in shield, it's this move all day. You can punish it on CC, but otherwise, this move frame traps into a lot of Samus's other stuff, like her smashes and tilts. Then, once she's conditioned you to stay in shield (don't let this happen), she'll mix-up into grabs and bombs.
Ftilt: This is Samus's safest poke. It starts fast, and ends fast, and can stuff your jump-ins really effectively. CCing keeps you grounded against it, but ultimately if she's spacing it well, you won't be able to punish for it. Blocking it will mostly keep things neutral.
Utilt: This is the move that will be used to condition you into camping, because it stuffs just about everything else. If you're hit while CCing, that's a hueg combo. If you're hit in shield, that's pokes, pressure, mix-ups and traps. If you're hit in the air, that's your stock.
Dtilt: It's a bad idea to get hit by this that's all I'll say on it. I think you can CC it at some percents, but it causes instant knockdown fairly early. Shielding it close can get you a free hit, but it has really long range and amazing pushback, so don't get cocky.
Dsmash: This has really deceptive range, and it can mean your doom if you aren't keenly aware of the fact that if you think you're spacing a move so Samus can't punish, she can always WD backwards and dsmash to punish any of your jump-ins. Shielding it works, and you might be able to get a good punish off of it. I shouldn't have to explain why you never never never want to CC it.
Fsmash: I think this move is situational against Falco, but it's another jump-in and whiff punishment option, and it mixes up with dsmash to make you wonder how to DI until the last second. Like dsmash, it's unsafe on block, but you can CC it for a few percent.
Dash Attack: I know it sounds stupid, but you need to be aware of this move and the spacings it's effective at. Obviously it's super unsafe on block and CC, but if a Samus has you conditioned to jump at bad spacings, this move will knock you down, combo you, or knock you off the stage. You can't really challenge it, because at best you'll usually trade. This move will also punish you to undercommitting to your jump-ins.
Missile: Don't rely on your opponent using this, because every Samus uses it differently. Since you'll be using your laser a lot, though, most Sami will use it sparingly. Be careful, though. One missile can do a lot to punch holes in your laser game, and that can be all Samus needs to get close. You can reflect this, but that carries with it a risk, since Samus can SH dair you in the reflector lag, and at certain spacings, can just dash attack the missile, clank to cancel the dash attack, then start mixing you up. PSing the missile is usually a better option, because you can act almost instantly.
Charge Shot: I hesitate to mention this, but it's worth noting. A lot of Sami just like having the little blinking light on their gun because their opponent doesn't like it. In other words, the fact that you are rightly terrified of the fully charged beam is the primary use Sami will get out of it. Other than that, when she has it, try not to waste your second jump ever, and just... be unpredictable. Mostly, the charge shot is used for punishes. Throwing it into combos is flashy and cool, and fun, but most Sami won't be pre-occupied with that. Also, be aware of uncharged shots, and don't let them catch you off guard. It's rare to see, but some Sami will troll you with it to see how you react.
Screw Attack: You are right to be terrified of this move. Honestly, Falco has no hard and fast option against it. Even those double shines you touted a few pages back tremble in the face of this move's might. You can bait it with a number of options, but that just lets Samus start poking you if she catches wise. Note that you don't even have to hit Samus's shield for this move to be useful--she can preempt any jump-in (including empty shffls) and beat it outright. I'm not going to sit here and enumerate all of the options I think you have here. You could do that better than I ever could. Just know that you'll need all of them.
Bomb: This move is weird. It's really punishable if Samus spaces it wrong, but it has some rewards that aren't readily apparent. Basically, if you commit to a jump-in on a properly spaced bomb, you lose the attack, and Samus starts mixing you up. If you undercommit, you get dsmashed. Alternately, if Samus catches you in shield with this move, she has a huge block advantage, because this move has two or three hitboxes with pretty good stun, and she can do anything out of the very first of those. It's also a projectile. In other words, if Samus bombs you, you want to stay in shield. Full Jumping can give you more space, but it's kinda telegraphed.
Nair: This move is best once you're conditioned to block. Samus will jump in, you'll block, then you'll wait an eternity before Samus finally slips that nair in on you just before landing. It's more a gimmick than anything. Usmash out of shield. You aren't Fox, but you still have a teensy bit of head invincibility. That plus CCing should be enough.
Dair: Surprisingly good spacer. Can't be CC'd. But it's pretty easy to see coming, like any of Samus's aerials.
Fair: Just CC this if you're on the ground at low percents. You can shine Samus for her troubles. Otherwise, this is the staple for making you afraid of full jumping, and taking to platforms. If you can bait it out, though, congrats. You've got Samus in the air. If you fail to CC this, you will get mixed up between jab, dtilt, dsmash, spot-dodge, or Screw Attack.
Bair: Midair spacer. Effectively, it's like a mid-air ftilt, just with KO-potential.
Uair: With fair, this move keeps you off platforms, and scares you out of full jumping. It's also a good combo move, and a full jump uair can be followed up with a missile to scare you into using your double jump. Other than that, just CC it.
Grab: Once Samus has you conditioned to shield everything, she'll start grabbing you. This leads to combos, tech-chases and edgeguards. ALWAYS be on the lookout. Fortunately for you, Samus waves her gun around in the air like a madwoman every time she standing grabs, so you can just spot dodge that bull and punish. Dash grab is faster, though. When Samus is running, she can dash attack if you try to jump, dash grab if you stay in shield, or CC fsmash if you spot-dodge or roll. If she's got a missile, and you can't PS it, she has even more options.
That should just about cover the on-stage part of the match-up. Hopefully, this kind of thing is something you'll find useful.
When you're edgeguarding Samus, a few things to keep in mind:
-You can snipe her bombs to nerf her bomb recovery.
-You can punish Samus for grappling. But be careful; she'll mix up the timing.
-Dsmash is really effective. But don't overuse it, or you'll get a ledgetech -> charge shot for your trouble.
-Colbol was reflecting Samus's bombs while she was recovering against Plup at Advent. Sometimes it worked and sometimes it didn't. Try to see what Falco might be able to do with this.
-Samus's no impact landing occurs very close to her ledge grab when timed properly. It's something of an ambiguous mix-up, so be mind-ful, and base your predictions off prior knowledge than on what it looks like.
-Samus has a stellar waveland. Be advised.
-CC her aerials until you can't CC anything.
When you're recovering:
Laugh at how bad Falco's recovery is.
NEVER GIVE UP AND BELIEVE IN YOURSELF!!!! (Okay that's a lie. Your stock is over.)