1. Remember to never split an infinitive. 
  2. Passive constructions are often used, but that does not make them acceptable. . 
  3. Avoid run-on sentences they are hard to read even when short. 
  4. Do not use no double negatives. 
  5. Use the semicolon properly, always use it where it is appropriate; and never where it is not. 
  6. Reserve the apostrophe for it's proper use and omit it when its not needed. 
  7. Do not put statements in the negative form when they can be written positively. 
  8. A subject have to agree with their verb and possessives. 
  9. No sentence fragments! 
 10. Proofread carefully to discover if any words left out. 
 11. If you reread your work, you will often find that on rereading that a great deal of needless repetition can be avoided by careful review and editing. 
 12. A writer must not shift your point of view. 
 13. Eschew dialect, irregardless of how often you see it in print. 
 14. And never start a sentence with a conjunction. 
 15. Do not overuse exclamation points!!! 
 16. Place pronouns as close as possible, especially in long sentences, as of ten or more words, to their antecedents. 
 17. Hyphenate between syllables and avoid un-necessary hyphens. 
 18. Write all adverbial forms correct. 
 19. Don't use contractions in formal writing. 
 20. Writing carefully, dangling participles can be avoided. 
 21. It is incumbent on us to avoid archaic constructions. 
 22. If any word is improper at the end of a sentence, a linking verb is. 
 23. Steer clear of incorrect forms of verbs that have snuck into the language. 
 24. Take the bull by the horns and avoid the can of worms that results from mixed  metaphors. 
 25. Avoid trendy locutions that sound flaky. 
 26. Never, ever use repetitive redundancies. 
 27. Spelling and grammer do count. 
 28. An author should be careful to use singular pronouns with singular nouns in their writing. 
 29. If I've told you once, I've told you a thousand times, resist the hyperbole. 
 30. Also, always avoid awkward or affected alliteration. 
 31. Do not string too many prepositional phrases together except to demonstrate a point about the structure of sentences for students of  English. 
 32. Always pick on the correct idiom. 
 33. Avoid overuse of  "quotation" marks. 
 34. It should be noted that it is unnecessary to call special attention to any statement. 
 35. The adverb always follows the verb. 
 36. Underlining is not a good way to indicate emphasis. 
 37. Spell checkers do not always choose the write word. 
 38. Prepositions at the end of sentences do not work out. 
 39. A careful writer can avoid gender traps without introducing awkward usages into her or his prose. 
 40. Last but not least, avoid cliches like the plague; seek viable alternatives.