Editing is a beast in and of itself, I know. What I am looking for is best practices in terms of the nitty-gritty, physical aspect of proofreading a manuscript. What are the standard symbols and markups for things like removing a sentence and replacing it with another, fixing tenses and word choice? Pencil or pen? I'd like to be consistent, even when editing my own work, so that I can be consistent and professional on the occasions that friends, colleagues and clients ask me to edit their work.