If they are sufficiently close to be hit by it, shine OoS. If in front but slightly farther, you can shield grab (1 frame slower) or usmash oos (2 frames slower), though the latter is worse when they're at 0. If they're further away, WD oos or if it's safe, laser oos. You can also roll or spotdodge during the startup of a move if you can see it or predict it and not have to worry about shield stun, or buffer roll or spotdodge if they aren't using a frame trap of some sort. Only spotdodge if you actually expect to get a hit off of it, for the most part.
Also, try to avoid ending up in shield in the first place. You may not be Fox, but upsmash has a great hitbox. If someone's jumping at you regularly, you can just flick up on the c-stick, and often completely beat the move they tried to approach with. You can also try to wall people out with bair (doing this towards them makes it easier to do a similar tactic to the "just upsmash" one I mentioned, as well as DD grab or shield grab). You can also dash out of the way, nair in place (if it won't trade) or, again most moves in this game, CC shine and ruin the opponent's day. The higher your percent, the less you want to do the last one, and you should avoid doing it vs. moves that primarily knock you downward, multihit moves, and moves that are sufficiently strong (say, Knee strength and higher). Also, uptilt is amazing, but like pretty much anything, can be dd grabbed, and can also be punished oos.
Even if you're super comfortable wavedashing max distance in either direction on a dime, maximizing dash dance distance, covering the entire foxtrot window, can run cancelling with crouch as early as possible, just adding in walking to your movement is useful. You're not confined to any set ranges, windows, or unactionable periods, and aren't forced to roll for pressing shield too early. It will also likely make it easier for you to react to things.
Retreating aerials are harder to punish, overshoot to beat dash dance. Or just laser.
Shooting a high laser allows you to go under it if they powershield, and a low one can be jumped over. You're in control of laser height, use it to your advantage.