Nothing helps make your message more effective than simply re-reading it several times. You can do this in your mind, you can read it aloud, or even have your computer read it to you. Whichever of those methods you use, listen for cadence and flow. The flow may sound “choppy” if you use a lot of unnecessary conjunctions (but, or, yet, and, because, nor, since, that …) or even worse: compound conjunctions (as well, as well as, as long as, so that, even if, in order to …) Excise these whenever possible if it doesn’t detract from your meaning. Misuse or overuse of conjunctions is only one thing that causes a reader to trip and stumble through your work. By re-reading your work you will probably find other word or phrase-choices that detract from flow. Comments and Suggestions are welcome here.
Update – Nov. 17, 2019
As an excellent example of writing which flows beautifully see this Atlantic article by Yoni Applebaum, senior editor: