for FADC :
Just hold forward for half a sec after you input the special (in fact it’s more “till your special is active/hit”).
From here all you need to FADC is go back to neutral and forward + MP + MK as fast as you can.
for SRK type moves :
f,d,df = df,f,df = df,d,df = f,d,f = f,df,uf = db,uf,db,uf = …
there’s situation and chars and people that will constantly succeed with some shortcuts that look harder than the default ones. You’ll have to test them.
My best example is doing Zangief st.lk xx green hand after a far MP. I personally use f.LK, df, uf.LP
for QCF x2 ultras :
db,d,df,d,df,f,u is what people use the most that covers the main possible mistakes trying to do it clean (aka : missing the first “d”, doing it too fast and getting a super instead)
for QCF x2 Supers :
Only if you cancel it from a QCF special, just forget the first Super QCF, the one from the special will count for the Super.
for Charge Ultras :
instead of charge db, df, db, uf you can do charge db, df, db, ub ridding the gate on the way back making it easier for some people.
There’s more with jump cancel & super jump cancel moves. Calling it shortcut is kind of misleading it’s more a motion adaptation to your style on a stick/pad.