I haven't read a whole Marilynne Robinson book straight through, but I mean to. Until that moment, I think this interview in The Paris Review gives you a peek at her incredible intellect.
On another note, I think it's helpful to note that across the board there is not a smidge of consistency in how successful writers work. Some of my favorite writers don't write every day, they don't write outlines, and they have a hell of a time answering questions about mechanics. Other writers I worship do in fact have precise methods and hours. How you work is how you work, so don't let any teacher tell you otherwise. If your writing sucks, it's not necessarily because you didn't write an outline.