It's important to note that you don't start there, with that kind of perspective. It takes getting a bad draft on the page, then massaging it, then backing away for a while via feedback. The three-part process (drafting, revising as best you can, getting distance via feedback) is a time-honored way to write in any genre. As John McPhee says in "Omission: Choosing What to Leave Out," his brilliant article in last month's New Yorker magazine, "Writing is selection. Just to start a piece of writing you have to choose one word and only one from more than a million in the language. Now keep going. What is your next word? Your next sentence, paragraph, section, chapter? Your next ball of fact. You select what goes in and you decide what stays out. At base you have only one criterion: If something interests you, it goes in-if not, it stays out. That's a crude way to assess things, but it's all you've got."
But eventually, you get kind eyes on the piece and you begin to see it differently, as a reader would. McPhee tells the story of one of his first editors at The New Yorker who wanted to delete a joke McPhee had in one of his pieces. It doesn't fit the rest of the writing, he said, so we should omit it.
McPhee refused, because he liked the joke. The editor conceded. The next day, McPhee came to him and suggested taking out the joke. It had taken overnight, but now he could see the disparity between the rest of the piece and this joke. One of his small "darlings" that didn't fit.
It's usually not bad writing, stuff that's horrendous and must be cut out. It's usually something that just isn't needed. That doesn't serve the writing anymore.
As you revise a book manuscript, chapter by chapter, you bring up the quality of those chapters you work on. Sometimes it's like the Golden Gate Bridge: as soon as workers finish painting it, they start over, because the first sections are now ready again. With my writing, I often enter this frustration: the chapters I revise are brought up to a level I like, and everything else falls short. Or, like my opening chapter of this current novel, are no longer serving the story.
It's a difficult process, often painful. But when it's done, there's a whoosh of energy as the whole piece becomes better. Almost magically.
And, I never throw anything away. The dead darlings are kept in a special document on my desktop. Sometimes, when I am searching for something to insert, I'll find the perfect section waiting in these discards.
You just never know.