Avoid run-on sentences that are hard to read.
No sentence fragments.
It behooves us to avoid archaisms.
Also, avoid awkward or affected alliteration.
Don't use no double negatives.
If I've told you once, I've told you a thousand times, "Resist hyperbole."
Avoid commas, that are not necessary.
Verbs has to agree with their subjects.
Avoid trendy locutions that sound flaky.
Writing carefully, dangling participles should not be used.
Kill all exclamation points!!!
Never use a long word when a diminutive one will do.
Proofread carefully to see if you any words out.
Take the bull by the hand and don't mix metaphors.
Don't verb nouns.
Never, ever use repetitive redundancies.
Last but not least, avoid clichés like the plague.
[HT: Advice to Writers]