"Self-Editing for Fiction Writers", by Brown and King,
Self-Editing for Fiction Writers, Second Edition: How to Edit Yourself Into Print
Remove *Fiction* from the title, because it can turn away those who are more interested in writing nonfiction. Published writers tell me it is the very best book for a writer, fiction or nonfiction, of any caliber or degree of experience/inexperience to IMPROVE their writing. It doesn't teach writing. It teaches editing.