As most of you already know, I have only two rules:
1. Never confuse the reader.
2. Never make work for your editor.
But my curiosity was piqued and I checked on the Internet to see what rules others may have. The following is Mark Twain's advice. Number 12 seems to encompass both my rules:
Mark Twain’s Advice to Writers
1. A tale shall accomplish something and arrive somewhere.
2. The episodes of a tale shall be necessary parts of the tale, and shall help develop it.
3. The personages in a tale shall be alive, except in the case of corpses, and that always the reader shall be able to tell the corpses from the others.
4. The personages in a tale, both dead and alive, shall exhibit a sufficient excuse for being there.
5. When the personages of a tale deal in conversation, the talk shall sound like human talk, and be talk such as human beings would be likely to talk in the given circumstances, and have a discoverable meaning, also a discoverable purpose, and a show of relevancy, and remain in the neighborhood of the subject at hand. And they should be interesting to the reader, and help out the tale, and stop when the people cannot think of anything more to say.
6. When the author describes the character of a personage in his tale, the conduct and conversation of that personage shall justify said description.
7. When a personage talks like an illustrated, gilt-edged, tree-calf, hand-tooled, seven-dollar Friendship’s offering in the beginning of a paragraph, he shall not talk like a refugee from a Minstrel show at the end of it.
8. Crass stupidities shall not be played upon the reader by either the author, nor the people in the tale.
9. The personages of a tale shall confine themselves to possibilities and let miracles alone; or, if they venture a miracle, the author must so plausibly set it forth as to make it look possible and reasonable.
10. The author shall make the reader feel a deep interest in the personages of his tale and their fate, and that he shall make the reader love the good people in the tale and hate the bad ones.
11. The characters in a tale should be so clearly defined that the reader can tell beforehand what each will do in a given emergency.
12. The author should say what he is proposing to say, not merely come near it.
13. A writer should use the right word, not its second cousin.
14. In crafting language, a good writer will eschew surplusage.
15. Do not omit necessary details.
16. Avoid slovenliness of form.
17. Use good grammar.
18. Employ a simple, straightforward style.