Don't edit when you're writing your first draft
When writing a document, a code review comment, or even a daily email, the key that slows you down the most is the backspace key. If you try and get every sentence perfect before moving on to the next it will take longer than writing a lot of imperfect sentences and editing them into something better. It can be hard to leave something you know is wrong. You’re only leaving it for a little while so you don’t break the flow and can get all your thoughts down though.
What you write in the first draft is the “marble” you’re going to carve the finished content out of. Until you have that you can’t see the final shape, what works together, and what doesn’t. A sentence that you didn’t like when you first wrote it might work nicely with something you write later but you won’t know that if you get stuck trying to polish the first sentence without having the rest.
When coding we have the “red, green, refactor” technique. Get the code working with its tests, then polish it, using the tests to make sure that you haven’t broken anything. This is similar to writing a first draft and then editing the code to make it cleaner and clearer.
Next time you are writing something see if you can intentionally split the writing and the editing phases and see if what comes out is better.