I'm really curious to know your recent discovered techniques on how to write a section that goes before a already written section!
i don't really have any fast techniques. usually it just involves asking a lot of questions and using process of elimination to eventually narrow it down. you have to be patient, it can take a while. but in the past few years i've succeeded at it enough times that i am confident that the answer is always there if you wait for it. some examples of questions you might want to be asking, let's say for example you have your chorus and now you're trying to figure out what the verse figure is that comes before it, examples of questions would be-- does it want the same chord for or different chord form? in many songs it is a no brainer that the verse and chorus use the same form, and that's fine. some songs it is supposed to be different. so first we want to narrow it down and see which one feels right for this song. often you get a clear answer yes or no. just a lot of narrowing it down. another thing which SOMETIMES works is see what goes well AFTER the chorus, like see what would be good for a second verse. but you're still going to be left with the puzzle of what will do best as the first verse, especially if the first verse starts the song. i have no good tricks for this, just spend time narrowing it down and trying things and seeing if they work. and i've gotten this now enough times that i always know there is a solution, so i know to be patient with it and keep asking questions