I have recently realized that my punish game with shiek is pretty awful. I see all of the mistakes that my opponents make i just cant seem to get there on time to punish them. Any tips on how to punish players for there mistakes?
One easy way to improve your punish game with Sheik is to focus on getting more grabs. Once you do that make sure you always get a satisfactory follow up out of your dthrow.
Sheik's punish game is pretty A-B-C when it comes to strictly punishing. Combo something into fair without getting CC'd or do dthrow->auto combo. When it comes to neutral and tech chasing though Sheik is a lot more complicated but that's pretty decent elementary advice
Another great way to punish your opponent is by controlling the stage. Even if you have no safe/guaranteed/easy hit stay on top of the situation and give them less room to work with. If you can make them roll or jump inappropriately you can capitalize on that and that leads to %, less stage for them, them missing techs/DI'ing wrong which gives you more % or control, or a stock