Effective drafting requires cutting. Sentences, paragraphs, entire pages. This is a good thing. Cut frequently, cut deep.
Write on anything through enough drafts, and it tends to grow branches. Your ideas wander and create their ideas, and every one of them deserves their due attention. The stuff you write will eventually wander off into tangents and go for page after page. This isn’t necessarily a bad thing. Branches are how trees and plants spread their leaves to gather light for photosynthesis and create the shade we enjoy resting under.
Too many branches might mean it’s time for pruning. Tying together several ideas can add weight and intrigue to whatever you’re writing about, but too many branches can cause your audience to wander off. A branch to your story can stretch, but you should be able to get back to where it started.
The editing room floor of any movie is usually ankle-deep in footage cut from the film (you know, back when movies were made with film). This is the stuff that made the DVD extras or was featured in the four-hour directors cut. It didn’t make the final cut, but it was still useful to someone.
When you write on an idea long enough, it grows branches. This isn’t necessarily a bad thing. Branches are how trees and plants spread out their leaves to gather more light to photosynthesize and create more shade and do what they do best.
Sometimes, though, pruning happens. You may have written a thousand words on a perfect idea only to discover you have wandered off on a huge tangent. If you wander off, so will your audience. A branch can stretch, but you should still be able to get back to where you started from. Cutting and editing can be painful. All of this work, for what?
Cut, but don’t delete.
What you trim out can serve as the foundation for a totally different bit of work. It fell on to the page for a reason, hang on to it. Keep a file or folder for the stuff you cut and revisit it when things are feeling thin.
Inversely, as some cuts work to slim down a project, other cuts can help things grow. Just about every writer I’ve worked needs to be shown how every sentence on the page could very well be a page of work onto itself. This sometimes gets worked out in editing: sometimes a sentence or two can be sustainable and stand on its own. Give it the room to do what it needs to do.