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.
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.
The approach to style is by way of plainness, simplicity, orderliness, sincerity.
Prefer the specific to the general, the definite to the vague, the concrete to the abstract.