Total Noob question - how to standing fierce into crouching strongXXboom

see title. I was LTTP for season 1 and missed out on all this basic shit. What is the trick to getting enough charge for this?
I get such envy watching other people do this with ease in their videos. My SFV guile is decent but i omit the standing fierce into crouching strong into boom combo ender from my play style as I can get it.

I am also having trouble finding input notation for the easier versions of the boom loop but that is a separate issue.

The instant after you press st hp your stick/pad should be going straight to downback. When the cr mp connects you can delay the flash kick input for a few frames and it will still cancel but slightly later, this is how you get enough charge time. It’s tricky at first but you should get the hang of it before too long.

The boom loop I use seems to be the easiest one. As long as you can get a sonic boom out and cancel it into v trigger you can start it from anything, but if you started it from st hp it would be:
st hp, cr mpxxhp boomxxv trigger activate,
dash forwards, st hp, cr mpxxhp boomxxmp breakxxlp break,
dash forward st lkxxany sonic break, cr lpxxany sonic boom, cr mpxxhp boomxxmp breakxxlp break,
dash forward st hp(at this point you can do any st hp combo to finish it)

It’s definitely hard.