With my students, I don't offer any simple tips like that, maybe because my own process is pretty messy, but when we workshop we talk a lot about the deeper subject, which is what the story or novel is about. I think defining a narrative's themes can lay bare a narrative's tensions.
Edan LepuckiI did a lot of this through writing flashbacks. Many of the flashbacks took place at Cal's school and I eventually cut them because they didn't seem essential and they slowed the pace of the story in the first third of the book. They were essential to me, though, in that I learned about my characters.
Edan LepuckiI am not sure how a novel changes the world. I think it alters a reader's perspective by asking him or her to see the world through another consciousness. That can perhaps cause people to see their own lives differently. Or just give a single day, a single moment, a slightly different sheen.
Edan Lepucki