Its important to use apostrophe's right. It's better not to unnecessarily split an infinitive. Only Proper Nouns should be capitalized. Use commas to keep a string of items apart in letters compositions reports and things like that. Watch out for irregular verbs which have creeped into our language.
Verbs has to agree with their subjects.
Avoid unnecessary redundancy. A writer mustn't shift your point of view. Don't write a run-on sentence you've got to punctuate it. A preposition isn't a good thing to end a sentence with. Avoid cliches like the plague.