No one can write decently who is distrustful of the reader's intelligence, or whose attitude is patronizing.
It is himself he is approaching, no other; and he should begin by turning resolutely away from all devices that are popularly believed to indicate style — all mannerisms, tricks, adornments.
Your whole duty as a writer is to please and satisfy yourself, and the true writer always plays to an audience of one. Start sniffing the air, or glancing at the Trend Machine, and you are as good as dead, although you may make a nice living.
Make definite assertions. Avoid tame, colorless, hesitating, non-committal language. Use the word not as a means of denial or in antithesis, never as a means of evasion.
Although there is no substitute for merit in writing, clarity comes closest to being one.
Vigorous writing is concise. A sentence should contain no unnecessary words, a paragraph no unnecessary sentences, for the same reason that a drawing should have no unnecessary lines and a machine no unnecessary parts. This requires not that the writer make all his sentences short, or that he avoid all detail and treat his subjects only in outline, but that every word tell.