the biggest thing is movement, if you are moving in linear single directions, its easy for them to know where you are going to land and go there, if you mix up your movements so you sorta zig zag back and forth to the ground and try and trick them and land away from them you'll get punished a whole lot less. Your double jump is an important resource here too and if you just burn your double jump straight away your options are a lot more limited, so dont use your double jump carelessly, use it for more mix ups, if they are ready to punish your landing with say a grab, you can make it look like you are about to land and then double jump, if you time it right they will whiff the grab and you get to punish with a falling nair or something.
Against slower characters you can just side B away so you never land near them, faster characters will punish this though and if you use it too predictably you'll get punished also, if you are gonna side B try to wait till the last second to commit, if they run away from you to get to where your sideB is gonna end to punish you, then obviously you can just land where you are, this might sound stupid but a lot of newer fox players will commit in their head to sideB a second or two before they do, and then just before they do the enemy runs away from them to get in position to punish the sideB, so you gotta be watching to see if the situation changes and if it does quickly force yourself to not sideB.
Against characters that cant really chase you offstage, when you get launched you can just drift off stage, sideB to the ledge, and get back onto the stage that way, against certain characters this is the ideal way to get back to the ground, against others this is a terrible idea and will get you killed/gimped a lot.
tl;dr
Biggest 2 things are MIX UP YOUR MOVEMENTS, dont move from A to B in a straight line or single direction, zig zag.
and watch them carefully and try to always land away from them, a lot of new players when they get hit up will just try land on their enemy with an attack, dont do this. It might seem like a good idea but people will expect it and you should never try approach them head on when you are in a bad position.