Common writing mistakes (editing for authors)

 Most people finish their book and begin looking for an editor or proofreader, but that's not always a good idea. Of course, you don't want any typos, but you can use Grammarly to catch most of them, and typos aren't your problem. To a great extent, the quality of the writing doesn't even matter that much. What really matters is the organization of the content, in an engaging fashion - which is mostly about withholding information to generate suspense and intrigue (what will happen next?) - that's pretty much the only thing you should be concerned with.

A quality developmental editor can help you tease out the main points of your story or narrative, and suggest fixes for plot holes, but they can't do everything, and they're expensive. You can do so much more on your own just by studying basics of plot and story structure, and avoiding the common writing mistakes most authors make.