IF A DOCUMENT is worth writing, it’s worth writing twice.
Although science fiction author Robert Heinlein famously claimed never to rewrite anything, he must be the only successful writer who can make that claim.
If you find it difficult to write well, remember that a first draft is just that. The trick to good writing is to dash off a fast first draft that captures the spirit of what you want to say. Don’t worry about spelling, structure or even perfect grammar. Now leave the piece for as long as possible. Then come back and re-read it.
Is the purpose of the communication clear? Write a sentence at the top that expresses that purpose, then rearrange the meat of your first draft below it. Cut out any repetition and tighten up long sentences. Summarize the main points in a final sentence, then tell the reader what you want them to do (e.g. “Call me with your opinions on this issue”).
If capturing a first draft on paper causes you trouble, try some different ways of marshalling your thoughts: draw a mind-map; make a list of bullet points; dictate your ideas into a voice recorder.
But always try to give yourself time to step away from your first draft and come back to it later. Good writing (and re-writing) takes time. As Pascal said, “This letter is long, because I did not have time to write a short one.”