Okay, vs Sheik in the neutral game: I would have to agree with Atma in saying that camping is a strong point in this matchup. Might just be me, but I usually wanna bait a little more than I camp. Just by chucking turnips, I feel like I never get anywhere, i prefer wavedashing and dashdashing, using a few jabs or FC nair in place. Another I like doing is at some point, when they jump or are moving a little closer, i like to run up and lightshield/shield in general over them and see how they react. If they were gonna come down with a move, the position I shielded might have messed up the spacing they were trying to get at. Also, you just capture more space. If she doesnt fastfall/double jump, I usually guess that they are not going to do anything, but you can experiment with this by nairing OOS. I'm starting to think that jumping out a little higher and FC nairing is better in this matchup than FH nairing, because of the laggyness. But if you mix it up, you can react to how to get in. For actually getting the hit, I like to crouch cancel and wavedash back, setting up for the dtilt. I have a bad habit of always wanting to do the combo from Armada vs Amsah 3 off the dtilt, but im gonna learn out of it. I usually dtilt, FC Uair, and then what ever move makes her go to the ledge, where I can techchase easier with FC Fair(covering get up attack, standard getup, tech in place) into dsmash(covering ways they could have rolled). If they shield, i just grab with the instant Fair>Grab. The from there, I toss turnips at the ledge, at that point, they just wanna come back so it's easy to punish once they do once you get back. The distance I like to stay is right at the end of the platform, to cover any waveland stuff. Besides that, like what Atma said, use nair OOS carefully, its easy to punish, and some things look like it would hit. I probably missed some stuff, I'll get back to other things if you have questions!
-Damn do i need to work on my paragraph structure