I actually disagree with a camping approuch to this mu. Marth has more powerful mid range zoning than we do which lets him approuch us if we're jumping firing lasers.
Getting grabbed by marth at 0 percent is still very scary, even if we SDI the dair he can still dthrow us like 10 times and f smash. I think this match up requires falco to have relatively flawless tech skill and a good understanding of where each characters do not have hitboxes.
I think falcos goal in this match up should be to get the center of the stage and use the positioning to force marth into unfavorable positions. I think SHDL is best used when you think marth will jump (but not when he's right next to you). Using your shield (and oos options), ftilt, smart lasers, bair, spotdodge ect are all going to be very important when hitting marth. But we really do not want marth to dominate the zoning. While its beatable if we're not on the sides its very difficult for falco to forcefully challenge marths nair in my experience (if someone knows a way I'm all ears though, so PLEASE POST!!!!)
Larry and fiction say to beat marth you wait for marth to swing his sword and then you hit him.
Also when you are landing in this mu there is almost no reason NOT to land with a silent laser (provided marth isn't in a position to hit you before you hit the ground). I mean it gives you a frame advantage LOLOLOLOL. Marth can't reflect or absorb it so if marth isn't in an immediate position to hit you it doesn't make a lot of sense NOT to land with it.
A lot of things marth has in this match up are really stressful so I think its very important for falcos to be able to consitently do the following things.
The ability to CG marth-I mean its bread and butter damage FOR FREEEEEE, that extra 40 percent we get could be the difference between winning and losing.
SDing out of marths side b- I saw FOW do this to mikehaze in the recent champion videos. (here is the link). I think its really important for falco players to get good at this, unlike our jab cancels marth doesn't really have options if he side b's except to continue it (except for gimmicks). Being able to avoid the last hit is really important since marths side b can send us off stage which is like the worst situation to be in in this match up.
http://www.youtube.com/watch?v=v_UrdfPEQRg
SDIng the dair on the cg-This could literally save you a stock, I mean you're GOING to get grabbed one day at 0 percent, plus the skills learning how to SDI this move will help you in other match ups like the ditto.
Juggling/not getting juggled.
When you are juggling marth I think up air is better than bair becasue of marths horrid down air. But that doesn't mean bair is bad, it just means if you're going to jump at marth trying getting under him and up airing.
Bair does however beat a lot of marths aerials.
But since our up air and dash speed aren't quite as good as metaknights we'll probably be hitting marth more as he's landing. Things like shielding, dash attacking, F smash work fairly well here. But becareful that you don't get swatted by marths aerials, marths will usually default to their nair or fair when landing before they default to airdodges if you are coming at them from the side.
Getting hit by marth kinda sucks, but if you can help it move yourself out of his fair range. Its going to be very important that you mix it up with attacks, double jumps delayed attacks, delayed airdodges, airdodges ect keep marth guessing.
Recoverying/edge guarding
RECOVERYING VS MARTH SUCKSSSSSSSS.
Don't put yourself in situations where you need to recover.
Let me repeat, try to avoid this situation all together, MARTH SHOULD BE HITTING YOU IN THIS SITUATION!!!!!!!!.
However since we're all eventually going to be put off stage there are a few ground rules.
Don't side b at the same time.
IMA REPEAT DON'T SIDE B AT THE SAME TIME.
Even if you do dumb side b's its better to mix it up than let the marth predict when you're going to side b and WHERE you are going to side b. This is pretty much true for every match up.
Try to save your double jump, and always keep in mind when you used it.
When edgeguarding marth I believe your goal should be to tack on as much free damage as possible. When he's recovering above the stage thats free lasers, shoot him. If he has RCO lag, shield (since he'll basically be forced to aerial) and hit him afterward.
There are otherwise to gimp marth however they all have some risk. One way is with a read grab the ledge and edge hop dair.
Our dair>his up B.
You might be asking why? Marths up B has invincibility. However it only has invince on start up which means any of our disjointed aerials will hit marth while he's moving upward. Ledge drop bair can work nicely (but you also run the risk of being stage spiked.
ALWAYS REMEMBER WHEN MARTH BURNS HIS DOUBLE JUMPP!!!!!!!!
I've recently been working on Falcos slow fall dair in this mu. you can hit marth out of his up b pretty easily with it but the only problem is making sure marth actually up bs when you're dairing. Unlike diddy who has an animation before the up b marth doesn't really. Within the next few days I'll be working on edgeguarding marth and will post some of my findings.
Stages
I think our best stages go BF SV FD, Delfino and frigate seem pretty up in the air. i think the transformation on frigate hurts both characters a lot(and it has a lower ceiling) where as delfino has some transformations that help falco a bit (like ones with lower ceilings).
I think BF is better than FD because I don't think we're really going to be able to out camp marth, and marth's 0 percent grab game on us is pretty strong. FD doesn't help us juggle but BF does (and marth doesn't need platforms to juggle us on).
Any stage I didn't mention I'd probably avoid. I'd also like to add that best stages are very subjective, a lot of it is personal preference of the player. So in the end I really think you should ban and counterpick whatever stages you are most comfortable with.
tl;dr
Get stage control
Don't camp like a ******, you'll lose stage control, you camp if it helps you maintain control over the center.
Learn all the technical aspects such as CGing marth, SDiing his side b and dair
Making sure to be smart about mix ups when recovering
Listen to this while playing in tournament sets
http://www.youtube.com/watch?v=eoMrkPLBuCs
Edit
if you disagree with anything I said PLEASE POST I CARE MORE ABOUT FALCOS AND MYSELF IMPROVING THAN I DO ABOUT BEING RIGHT!!!.