How do you set up a U2 trade with shoto characters?

So I searched around for awhile to try and make sure this hasn’t been discussed it its specifics, if it has I applogize, I could not find it anywhere. So here goes…

How exactly do you guys try to bait out or react to the fireball trade / Ultra 2 (U2) against shoto’s? Are there certain things you guys do to set it up and pull it off on a regular basis? or do you guys just do it on reaction?

For example: After a (roundhouse sweep) blocked, after the second hit a lot of Guiles like to sonic boom (sb) after. Some shoto’s pick up on this and try to match the sb with a fireball – I know its worked at least on two occasions for me where I buffered the U2 and if I see the fireball motion coming out, I hit all three punches - fireball trade U2. If I don’t see the fireball motion I don’t press the buttons and you just see my Guile twitch back n forth real quick.

What other ways or situations do you guys buffer the U2 movement to catch a shoto fireball trade? I know a lot of shotos are aware of the U2 trade and are wary of it, but sometimes if you condition your opponent enough, or maybe its just there habit to throw a fireball at a certain time, we Guiles can catch them slippin with a U2 trade. Or am I just trippin and I should be able to just bust a U2 on fireball reaction?

(NOTE: I am not perficient in the FA > dash > U2 yet. So other setups other than using that would be nice.)

Any tips/assistance would be appreciated.