Writers must constantly ask: what I am trying to say? Surprisingly often, they don't know.
William ZinsserNever say anything in writing that you wouldn't comfortably say in conversation. Be yourself when you write. If you're not a person who says 'indeed' or 'moreover,' or who calls someone an individual ('he's a fine individual'), please don't write it.
William ZinsserThe best way to learn to write is to study the work of the men and women who are doing the kind of writing you want to do.
William Zinsser