BBC Radio 4 has a season of George Orwell and his work. These are his ‘rules for writers’ most of which I break everyday.
(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 or jargon if you can of an everyday English word
(6) Break any of these rules sooner than say anything barbarous.
I also value one by Winston Churchill that echoes some of Orwell ” Broadly speaking, the short words are the best and the old words best of all”