Unless cost is not an issue for you, you can save yourself a lot of money that would go to an editor—and hone your writing skills in the process—simply by listening to your work. You’ve probably spent a good bit of time in the creation and revision of your project. Your brain is accustomed to a visual interpretation—that voice in your head when you’re reading silently. But when you read aloud, the words come out of your mouth and return to your brain through your ears. You will be amazed at what you will find when you employ your sense of hearing for a change.
Either read it aloud to yourself, stopping to make notes along the way, or have a friend read it to you as you make your notes. You will discover grammar and punctuation problems, ditsy dialog, unintended repetition and more. Sure, you’ll have to spend more time at the keyboard, but you won’t be paying an editor for something your brain was perfectly suited to do instead!