Writing and editing are, I think, very different activities—the first involves creativity, and the second is more about applying logic and making sure you're following "rules" (not only simple rules of grammar but also complex rules of style and readability).
That's why, in an ideal editorial situation, one person writes and another person edits. But I don't live in that perfect world. So with important documents, if I have time (and especially if I'm writing something long), I try to write and edit separately. This is my self-editing process:
- I write: trying not to self-edit, I finish a draft.
- I let some time pass: even a few hours can allow me to read with fresh eyes.
- I print the text and review it with a colored pencil: I'll often find things on paper that I won't find on screen, and removing myself from the writing environment prevents me from slipping too far back into "creative mode."
- I implement my revisions (and repeat steps 2 and 3 if I did heavy rewriting).
- I read the document aloud: even if I just whisper, this helps me ensure readability—and I often uncover sneaky typos at this stage.
- I run a spelling checker: I leave the spelling checker off while I'm writing; I find that it fades into the background if it's on throughout the process.
- Read the first and last lines of each paragraph to check transitions.
- Turn the document upside-down to check formatting: this allows you to see the document without reading it.