Haven't seen a whole lotta OS talk but what have you guys been working with?
I've begun to implement OS's during the neutral and wakeup that I'd like to share. I've confirmed these all work via manual inputs as well as setting the training dummy to do them, to take out player error.
On wakeup I like to use f12b4 roll OS. After b4 input roll then any direction. Very easy and extremely useful, seeing as it helps make the high low guessing game alittle more favorable for Mileena since you can commit to a low mixup without penalty of being punished on a bad guess.
Next we have my personal favorite 21u4/roll OS. Admittedly you need some decent finger dexterity for this one due to the tight a input window. After 21 input roll then immediately u4. A proper input will give you roll after a succesful 1 no matter if the opponent blocked or hit by 2. I say this because in certain instances the OS would not work properly if your inputs weren't timed right. Sometimes there'd be no roll on hit or u4 on block, all due to that first hit. However on the plus side 21 is +10 on hit and -7 on block. So you're not completely losing pressure, and it's still relatively safe, if you mess up.
Then in neutral there's b12. Standard OS that you can fire and forget. Same as as before b12 input roll, cancel with a direction. Now in the Milena mirror I noticed how f1 has an issue hitting non ex ball roll so I spent some lab time and found meaty b21 can stop it. Now the 1 is a low so you can mix in ex roll for a 50/50 and you can OS roll after the 1 for a safe mixup.