Short Sentences.
The philosopher Pascal once apologized for writing a long letter; if he'd had more time, he said, he'd have written a shorter one. Mark Twain said he didn't write Metropolis because he earned the same amount for writing City.

Short Paragraphs.
One idea, one paragraph.

Active Voice.
Not "the dog was walked by the girl."

Necessary Words Only.
"Advance planning" equals "planning." Put the news in the document's first paragraph. Don't overload the reader with adjectives and adverbs. When it's done, cut it 10%.

Simple Words, Action Verbs, Concrete Nouns.
"It behooves the writer to avoid archaic expressions" may be a true statement, but it's a weak sentence. Use the S-V-O (subject-verb-object) as the basis of any sentence. When jargon tempts you, remember that your audience doesn't have the same vocabulary that you do.

Consistent Tenses.
When you change tenses, have a reason. Don't be afraid of the present tense.

Avoid Clichés Like the Plague.
Enough said.

Parallelism Creates Power.
Organize thoughts in parallel and use parallel construction to state them: "Our company locates oil deposits, refines petroleum products, and sells gasoline."

Show, Don't Tell.
Follow a generalization with an example. When explaining a complex process, use everyday analogies.

Anecdotes and Quotations.
Use plenty. Don't be afraid to use them.