A non-fiction writer pretty much has the shape of the figure in front of him or her and goes about refining it. A work of non-fiction is not as difficult to write as a work of fiction, but it's not as satisfying in the end. ↗
I think most serious writers, certainly in the modern period, use their own lives or the lives of people close to them or lives they have heard about as the raw material for their creativity. ↗
I think the hardest part of writing is revising. And by that I mean the following: A novelist has to create the piece of marble and then chip away to find the figure in it. ↗
If I had a plot that was all set in advance, why would I want go through the agony of writing the novel? A novel is a kind of exploration and discovery, for me at any rate. ↗
What I have in advance are people I want to write about and a problem or problems that I see those people encountering and that I want to explore - it all proceeds sentence by sentence, paragraph by paragraph, and scene by scene. ↗