All you need to know about style

From William Safire, quoted in the Guardian Style Guide:

“Do not put statements in the negative form. And don’t start sentences with a conjunction. If you re-read your work, you will find on re-reading that a great deal of repetition can be avoided by re-reading and editing. Never use a long word where a diminutive one will do. Unqualified superlatives are the worst of all. De-accession euphemisms. If any word is improper at the end of a sentence, a linking verb is. Avoid trendy locutions that sound flaky. Last, but not least, avoid clichés like the plague.”

You can find the Guardian Style Guide online. It contains more than just writers’ in-jokes, and is a useful resource for writing advice of all kinds.