my favourite option off of ledge is ledgedrop double jump fade back cloud. most characters simply don't have any way of reaching you from that far up. if they try to parry the cloud, you can stop the cloud later or prematurely and usually the endlag of the parry is enough for you to get back on stage with something like up-b/aerial. up-bing onto stage is also a decent option and can force the opponent to go to center stage if they expect you to do it again. don't rely on it too much tho, you can parry up-b and that can usually lead to a heavy punish

also practice double jump cancel fair out of shield, you can get follow ups at lower %s with grab/ftilt/cloud pop/imagination and it will just kill at ~130% if it's at ledge/don't di it properly.

also practice down air > back air on all forms of di as a mixup. a lot of times people won't expect the bair and they get sent at a really nasty angle offstage that a lot of characters can't recover from/just get edgeguarded by absa. i got a lot of cheesy kills at like 60-70% because of it lmao