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.
Via Lists of note