Excerpts from Politics and the English Language (attached .pdf):
"A scrupulous writer, in every sentence that he writes, will ask himself at least four questions, thus:
"1. What am I trying to say?
2. What words will express it?
3. What image or idiom will make it clearer?
4. Is this image fresh enough to have an effect?
"And he will probably ask himself two more:
"1. Could I put it more shortly?
2. Have I said anything that is avoidably ugly?"
"I think the following rules will cover most cases:
1. Never use a metaphor, simile, or other figure of speech which you are used to seeing in print.
2. Never use a long word where a short one will do.
3. If it is possible to cut a word out, always cut it out.
4. Never use the passive where you can use the active.
5. Never use a foreign phrase, a scientific word, or a jargon word if you can think of an everyday English equivalent.
6. Break any of these rules sooner than say anything outright barbarous."