At times when I’m writing a manuscript, I find there is something I want to change or omit altogether. It might be a mere paragraph or it could be a page or more. Whatever it is, I don’t discard it. Instead, I cut and paste it into the back of the manuscript I’m writing. I also add a heading so it’s clear what it’s about. Invariably, I find myself going back to it at some point and using it, or part of it, thankful that it's been saved.
What are your methods?