1. Use an orderly writing process
The advantage of writing over speech is that you have a second chance to say it better. But you have that chance only if you make the opportunity.
Write early and quickly without criticism; then take some time to reconsider critically later. The less tension you put on the front end of writing (the drafting) and the more you put on the later stages (revising, editing, and proofreading) the better the writing will be.
You will be able to act on principles for improving your writing only if you use a writing process that includes two steps: a means of discovering the ideas and a more deliberate reconsideration of those ideas.