Creating an outline from a finished draft rather than before writing one, so you can see the structure you actually built and find where it breaks down.
A reverse outline is an outline you create after writing a draft, not before. You go through your manuscript chapter by chapter (or scene by scene) and write a brief summary of what each section accomplishes: what happens, what changes, and what information the reader gains. The result is a structural map that reveals pacing problems, missing connections, redundant scenes, and plot threads that go nowhere.
Most writers' outlines (if they make one at all) don't match the book they actually wrote. A reverse outline shows you the real structure of your draft, not the one you imagined. It's the fastest way to find structural problems because you're looking at the whole shape of your story from above, rather than getting lost in the sentence-level details that dominate normal reading.
Each chapter or scene entry should be one to three sentences max. You're trying to see the forest, not catalog every tree. If your reverse outline is longer than two pages for a full novel, you're going too deep.
Track more than just 'what happens.' For each section, also note the emotional shift, the character development, and the reader's information state. A scene where nothing happens plot-wise might still be doing critical character work, or it might genuinely be dead weight.
Open your current draft and go through it chapter by chapter (or scene by scene if you don't have chapters yet). For each section, write one sentence answering: 'What changes in this scene?' If you can't answer that question for a particular section, mark it with a question mark. When you're finished, look at your list. How many question marks do you have? Those are the scenes that might need to be cut, combined, or rewritten.