Play another person who knows how to play, and for every time you get hit, think about why. Think about what position you were in and what actions you were in before hand. Think about avoiding the situations that lead to you getting hit in the first place, and choosing different options once you end up in those situations.
Some general stuff. CC has been on the rise again lately, so grabs are your friend, jabs are your enemy unless the opponent is airborne, and you want to spike or meteor (the former seeing as you play Falco) to start up offense close vs a grounded opponent (i.e. start a combo from dair if the opponent's grounded), and otherwise poke with stronger moves rather than go all in.
Don't laser too close, as you can be hit, and if it's clear someone's trying to move in on you lasering, either get out of there or start stuffing and walling their advance to the best of your ability (still be wary of cc and potential OoS approach).
Retreating aerials (drift away from the opponent) are harder to punish in most ways: from stationary positions (i.e. OoS), off of a dash dance (especially with a move they need to get close with to land, and off of a projectile, though they have more room to put the projectile out in the first place. Larger moves that you might be able to stuff by going in (various Ftilts and Fsmashes) are far less likely to be stuffed and can still punish you if they approach or otherwise get close enough.
Rolls and spotdodge are good, but shouldn't be predictable or done in positions where it's easy for the opponent to react to and punish (don't roll into the opponent if they aren't moving in on you or busy with some other action, like using laggy moves, ever, and spotdodge is almost always worse if you don't think you can directly get a punish from spotdodging the attack).
Grab is important, so try to limit the opponent's capacity to grab you through hitbox placement and movement. Once grab becomes hard to land, shielding after landing a hit you can't combo off and doesn't send the opponent far away may become desirable, as many opponents will attempt to attack you in hopes that you'd continue a combo attempt and fail, attempt to keep zoning with attacks (which you should if you can do so without getting hit and are unable to start a combo), and generally, in the startup of something you're doing. Remember, most grabs are among the lower-ranged attacks a character has, and the more limited the time they have to hit you, the less likely they are to use it.
Make sure you have a fast out of shield game, and be ready to wavedash OoS immediately if the opponent isn't close, or but it's also important to punish options with more range that are still laggy.
The lower the aerial, the less lag you're in comparatively for hitstun and shield stun. This translates to lower aerials being better for extending a combo and vs shields (until it takes you out of the auto-cancel window).
To avoid grabs more proactively, obviously they can't grab you (or attack you at all) if you're comboing them or have grabbed them yourself. Downtilts are strong vs many ground based approaches: wavedash anything where they aren't trying to outrange the dtilt (but even then, you're likely CCing), ftilts are okay simply because of range (much more so at higher percents), and bairs straight up outrange grabs and stuff various other approaches (better for preventing startup on drift in, but this is less safe on hit in every way, yet also has more potential to combo).
Dash dancing is important, use it to try to get the opponent to react, to whiff punish moves, and make your position less obvious by the time an attack would reach you.
Be ready to cover rolls and spotdodges. Roll inward is more important to punish than away, since away means you gained stage position anyway. Spacing yourself and dash dancing inward to beat out approaches, long ranged pokes and out of shield play also positions you to cover roll in, and dashing back towards them lets you catch the spotdodge, but any sufficiently non-laggy movement option can achieve the same.
Don't give up too much stage position, unless you master your ledge game perfectly, it's better to have more stage (and unless you'll end up on the ledge, it's better to not be in the corner even if your ledge game is perfect)
DI is incredibly important. When you're still on the ground, downward DI and ASDI can avoid a lot of potential combos assuming you're ready to Amsah tech, and this can also work in midair vs moves with more horizontal knockback, assuming there's stage behind you and you're low enough. Otherwise? Learn to recognize when combo moves or KO options are coming and DI appropriately. To avoid combos, you want to distance yourself from to the opponent, or end up back on the ground/out of hitstun as quickly as possible. The former generally translates to DIiing away in some form. To survive a KO option, you want to go towards the corner, of the blast zone, or at least as high as possible without dying off the top as you won't always be able to recover from the corner, or may have more limited options.
Work on punishes: you want them to be as strong as possible yes, but at minimum you should try to make it so that you never get hit or lose position for attempting one. Try to recognize when and what you can hit with that puts them away with no chance of retaliation, or forces them to a grounded state with minimum lag. Obviously a 0-death is ideal, but if you're getting 40% off of every hit and gaining position or otherwise end up out of lag far before the opponent, you're doing fine. You need to recognize how they can DI off of anything (as well as how prior positioning affects this), and thus the potential consequences of a given hit before you ever land it, but immediately recognize what you can do next as and after it connects.
Try to avoid being repetitive and predictable to the point that what you're doing before the opponent is under your control (knockdown, combo, tech-chase) they have a significant amount of time or number of cues to know what comes next (unless they aren't punishing it). By this I mean, don't do something like laser twice at spacing X and then aerial approach on the same timing without changing positioning in different ways between steps. Even if you are mixing up exactly how you're these things, it's probably for the best that it isn't fundamentally 2 lasers -> aerial every time.
Pay attention to what your opponent does, and what circumstances (positioning, percent etc), and become so confident in what you're doing you don't have to pay attention to yourself (not that you shouldn't still do this). This is probably the most important thing, period.
