Be Considerate of your reader.
Be Concise. George Bernard Shaw once said, I'm sorry to have written such a long letter, I didn't have time to write a short one." It's hard to be concise.
Be Correct. If at all possible, two or three people should read a hard copy at every step along the way. Make two or three copies, so that everyone's not reading your comments. Finish your copy a couple days early, so you have the distance from the story to be one of those readers.
Be Clear. Clarity depends on words, grammar, flow and structure.
Be consistent. Provide the reader with what you seem to promise up front.Let's say that you start your story with an anecdotal lead. That doesn't mean to the reader that everything that follows that lead is going to be narrative and experiential. But it does suggest you're taking a somewhat less formal approach. Don't fool your readers with a formal beginning when the rest of the argument is informational fluff. That happens very often and it's not right.
Be complete. There are two kinds of completion. Informational completion is answering the reader's questions. However, whole books can be written about subjects that we write 500 words about. So we want to give the atmosphere of having selected the right material for the reader. This is where the editor has to know what must be kept in and what can be kept out.
Be Credible. Credibility comes from knowing your audience, using credible material from credible sources. If you analyze the best writing, there is a conversational quality to the language, almost as if the writer is sitting in an easy chair. The reason is that writers and editors have discovered that people do more listening than reading. Therefore they feel more comfortable with a language of sound. For that and other reasons, I encourage you to read all copy out loud. The ears are much less forgiving than the eyes.
Avoid Jargon. If you use jargon, at least insinuate what you mean. Jargon gets cliched very quickly.
Avoid Euphemism. Euphemism is language that lies.
Avoid Status Symbol Language. It's the language of the professional synergism, syllogism, interface, quid quo pro, infrastructure, recidivism, paradigm, post-modern, post-industrial society, explication, replication. These are words readers sort of understand but don't quite, and they don't sit with a dictionary when they read your material. We have 23-25 million functionally illiterate people, and 60 million people who read below a ninth grade level. You have some of those among your readers. Please help them, don't hinder them.
Avoid Bad Grammar. Don't permit it. We are the guardians of the language.
Avoid too many long sentences. Most of us are not very good at writing good long sentences, and on top of that we don't have very good readers. The result is confusion.
Cut Back on the Fat. Here's Russell Baker on "American Fat": "Americans don't like plain talk any more. Nowadays they like Fat Talk. Show them a lean plain word that cuts to the bone and watch them enlarge it with thick, greasy syllables front and back until it wheezes and gasps for breath -- until it comes lumbering down upon some poor threadbare sentence like a pack of iron on a swayback horse. 'Facilitate' is typical of the case. A generation ago only sissies and bureaucrats would have said 'facilitate' in public. Nowadays we're a nation of 'facilitate' utterers. 'Facilitate' is nothing more that a gout-ridden overstuffed 'ease.' Now why has 'ease' fallen into disuse among us? It's a lovely little bright snake of a word which comes hissing quietly off the tongue and carries us on without fuss or French horns, to the object which is being eased. It's English at its very best. Easing is not one of the great events of life, it doesn't call for Beethoven. It's not an event to get drunk on, to wallow in, to encase in multiple, polyangenous syllabification until it becomes a pompous word like 'facilitate.'" We want to avoid American fat.
Beware the disease of Thesaurusitis. In one of his columns on language James Kilpatrick said that if the word is 'banana," and you need to use it four times, don't use it three times and the fourth time say "an elongated yellow fruit." The verb "to say" has 50 synonyms probably â let's use to say. Maybe a "conclude," maybe a "continue," but avoid all the "explains" and "exudes," they just get in the way."