Against floaties just space aerials, mainly Fair and Bair, and needle from platforms at lot. Force them to come up after you and hit them with needles --> Fair and combo Fair into more Fair and/or other aerials probably Nair or sh rising weak Bair --> ???. Against Puff avoid grabbing unless it's obvious you can. Against Samus/Luigi do lots of needle --> grab. Against Peach do lots of D-smash.
Against mediums/semi-floaties just WD back and F-tilt a lot when they approach, move around with platforms, make them come after you when you're on a platform and then dash off and Bair them or something. Grab a lot. Shield WD out of shield when they attack and then punish.
Against Marth just grab a lot and CC to dash grab, shield grab, or roll if he tries to pressure you. If he's retreat Fairing just space so the blade misses barely and then dash attack or grab in his lag. Dash Attack lots. Grab lots. Needle lots. Avoid doing D-smash. If you wanna SH Fair him time the Fair really late to avoid CC grab. In general do your aerials really late on Marth or just while rising so you don't get CC grabbed and buttfucked for it.
Against space animals do moves. Hit with those moves. Fair and Bair are good moves. D-smash is also a good move. WD back and F-tilt against Fox a lot if you space perfectly it beats his Nair and if you space less perfectly it beats his Dair. Pivot grabbing through his Nair is also good but harder so not recommended. Bair is good. D-throw and then do stuff. Against Falco just Nair out of shield a lot and then platform camp and force a needle through and then pour on aggression.
Against Falcon just be prepared to be very patient because they tend to just DD camp and don't fall for stupid dash tricks and limit his movement as much as you can. F-tilt him through his approaches, and WD back F-tilt, crouch under his grabs, CC his raptor boosts into grabs, if you do go into the air do your aerial really late so you can't be shield grabbed or punished for it with raptor boost going under it or anything, and when you grab just 0-death tech chase with regrabs. Avoid doing D-smash or Dash Attack unless you're tech chasing because those are easy to punish with Dair and Sheik is pretty easy to combo if you know your percents. Nair out of shield a lot.