General advice - Punishing landings:
Shieldgrab
Pros: Can beat anything as long as they land in front of you.
Cons: Doesn't kill, doesn't deal a ton of damage, is really obvious.
Summary: Probably the safest landing punish available, which makes it a decent option at any point in the game.
Charged Up Smash
Pros: It kills.
Cons: It's somewhat slow, it doesn't have a very long-lasting hitbox, and it's very punishable if it fails.
Summary: Just about the heaviest punishment you can get on someone trying to get back on the ground, but with it comes a lot of situationality and risk. Only viable if you can bait an airdodge as they're falling near the ground, otherwise will almost certainly either miss or get interrupted.
Charged Down Smash
Pros: Quick, covers a lot of ground, hard to avoid
Cons: Still a charged smash that can be seen coming, doesn't lead into anything
Summary: Probably a good punish for people who insist on air-dodging right behind you or something similar, but other than that's it's just a safe bet for possibly less reward than grabbing.
Forward Tilt
Pros: You just landed a forward tilt on the opponent. You figure it out. Also, decently long-lasting hitbox for easier timing.
Cons: Vulnerable to a lot of aerials
Summary: Once you get to that magical percent, this is probably the most rewarding way to catch an air-dodge. Don't forget about this option.
Up Tilt
Pros: Very long-lasting hitbox, beats out a lot of things, safe
Cons: Doesn't do much of anything
Summary: A nice, quick reminder that falling at you with aerials isn't always going to work. Useful as one of Sheik's most disjointed attacks.
Down Tilt
Pros: Low to the ground, can avoid a lot of aerials, decent range, very easy to time
Cons: Sheik's least useful tilt
Summary: Sends in a marginally more useful direction than Up Tilt at certain percents. Doesn't beat out as much, but Sheik crouches so low that she can just dodge aerials instead.
SH Neutral Air
Pros: Weak hit can set up for dash attack, dash grab, (sometimes) ftilt, running usmash, etc.
Cons: Puts yourself into the air waiting, requires a lot of pre-emptive action
Summary: You can either hit hard with an exact timing nair, or catch air-dodges and set up for
interesting punishes with it. The nair punish takes a bit of reaction to abuse properly, and is best used at higher percents.
Nothing else is particularly useful for punishing landings.
