Focus attacks - how to utilise it?

How should focus attack be used? Obviously, there’s the basic, crumple > ultra and FADC, but you can also use it to punish jump ins (if timed & spaced correctly) and dash through/absorb projectile moves. What else can you do with it? How and when should it be used? This is where I really fall down and struggle to understand/take full advantage of this mechanic. I have tried to fathom how best to use it from watching other players, but I have a feeling some of the players I’m watching might not be using it to its best advantage either - perhaps too many focuses to bait out something and actually taking unnecessary risks in doing so.

Yes, in some instances you can AA with an FA if they use a slow or obvious attack. It can also be used as a fakeout at L1/L2, if you cancel it into a dash. FA/FADC use also varies from character to character. While some are reliant on it, some don’t get to use it as much.

Going through Youtube for match and tut vids can help you get ideas on how to FA well with your character.