Don't say "per day" or "per year," but "a day," "a year"; per is a Latin word and can be used only before a Latin noun, as "per diem" or "per annum."
Don't say "the meeting convened"; members might convene but a single body cannot.
Don't "claim that" anything is so; you can "claim" a thing, however.
Don't say "Mrs. Dr. Smith," just "Mrs. Smith."
Don't say "between" when more than two are mentioned.
Don't use "proven" for "proved."
Don't confound "staid" with "stayed."
Don't say "different than," but "different from."
Don't split infinitives or other verbs.
Don't use "onto."