It is MU dependent, which is why it is tricky to use it often. The most Obvious is F+3 to punish them for poking or waiting. I find that I have most success If I walk back a couple of steps (try not to dash back) and do another ss or close GS. If they have a really fast normal, then your best bet is to stand still and D+3 to catch them while they advance forward. And yea lol, people love to jump after a blocked SS so you can obviously punish that. The key is to know what you are going to do immediately after the SS, otherwise your spacing and advantage will be wasted.