on Writers Helping Writers:
Part of the trick of hiring an editor is knowing when your manuscript is ready to hand over to them. There’s no point submitting a draft that you already know has POV issues or structural problems. The ideal situation I like to be in when I deliver my manuscript to an editor is that I think it’s perfect. Of course, it never is, but “perfect to me” means I’ve done everything I know how to do. That way, the editor will teach me something.
There are three main types of edits: developmental, line, and proofreading. At each stage, an author can do a lot of self-editing to create a “perfect-to-me” manuscript.