I proofread as much as I can. If I miss something, I edit.
A pet-peeve of mine is when someone uses the preposition 'at' at the end of a sentence. IE, where did you put it at? Argh!! Drives me crazy.
How about 'anyways'? That's another one that gets me. My mother reminded me over and over that it is 'anyway'. Now when I hear it, I think of her reminders.