It's funny how the creative process is very different from one person to another. For example, JK Rowling has a lot of extraneous background stories, family stories, and futures which are not in the books. But William Gibson has said that once when asked "so during this book, what's happening in Denver?" he said: "I have no clue". He laughed and said "the whole thing is one molecule thick." He apparently does not need to have revealed to him one iota more than just what is going into the book.
Gibson is also, so far as I know, an extremely intuitive writer. Whereas some writers work via an intellectual process, based on what they've learned about how stories work and so on. Some, like my old teacher Algis Budrys who died last year, work one way sometimes and the other way sometimes. He once woke up in the middle of the night with a whole long story complete in his head. He got up and wrote it all down in sketch form, which he appreciated the next day, for after sleeping he had forgotten it.