When you’ve found someone who seems like a decent candidate so far, make first contact. (The contact form on the website is fine as a first step.) Introduce yourself and state what you are looking for (a developmental critique, copyediting, etc.). Give a very brief description of your project, including its genre and approximate length. Give an idea of your planned next step and any deadlines (even if only approximate ones). For example, have you already signed a contract with a subsidy press for publication next fall? Are you planning to submit the manuscript to publishers and/or literary agents after editing?

A good editor is invaluable when starting out. Later on it perhaps depends on how complex the story or writing is. Editors can be looking for similarity not originality. The final script a poor representation of the original story or article. An article of mine, which was picked up by Wikipedia for its originality and informative ideas was given forty edits from around the world! It was like a mechanical invention rather than an interesting article in the end!
Book editing is both subjective and not. There are rules, and yet the rules of writing are often intentionally broken. You want to find someone who knows the rules, who will fix the writing, and who’s flexible enough to know that voice is sacrosanct, and that editing out colloquialisms, slang, and humor is a no-no (unless it’s overdone or not working, that is).
Moreover, the casual distinction between a (developmental) “editor” and a “copyeditor” can be a bit simplistic, particularly in a self-publication or even vanity-publishing context. A self-published author may barely have the budget to hire one editor, so that editor needs to be able and willing to blur the lines between developmental editing and copyediting. The editor must also be accustomed to working with authors of a variety of strengths and weaknesses, including many whose work would not, in fact, have been accepted by a commercial publishing house in its current form. I have come to take great satisfaction in taking a new or newish author by the hand and helping them find ways of making their work the best it can be. Of necessity, this must include line-by-line correction of grammar and style (often a surprisingly great amount of such correction), but can rarely be limited to that.
Our editing services are for authors who want premium book editing for an affordable price. We’ve negotiated special rates with an exclusive network of editors from around the globe. These editors work with traditionally published authors in every genre, including many on the New York Times Best Sellers list. Now, self-published authors have the opportunity to work directly with these topflight book editors.
Really great advice. I just wish editors and proofreaders were more affordable. I find that the cost often dissuades writers from hiring help, even though it’s a really important investment. I like PaperBlazer (https://www.paperblazer.com/hire-a-proofreader-or-editor-for-your-novel/) since it’s more affordable than a lot of other editors. The other comments here are very helpful as well.

You draw distinctions that use idiosyncratic definitions of some fairly standard terms. For example, Chicago defines the terms “manuscript editing,” “line editing,” and “copyediting” as synonymous with each other, and none of them as synonymous with “mechanical editing,” although that is one element of them. Certainly, I agree that an author has a right to expect more than merely mechanical editing unless that is specifically what they have requested. However, I cannot agree that the only route into competent and appropriate freelance editing is internal employment within a publishing house, and that the only clients who should be counted as a relevant part of a freelance editor’s curriculum vitae are those who are traditionally published.
My facility with words derives from a love of literature and a background in French, teaching English, and editing. Throughout my academic and professional experiences, I have had the opportunity to work on a variety of texts, from academic papers to blogs to web content to novels while respecting English grammar and mechanics within the context of various style guides, including AP, CMoS, APA, and MLA.
It can take some time to find the right editor, so you may want to start asking around even before you have a text that is ready to send. If you know a fellow author who can recommend someone, that’s wonderful, but if not, it’s fine to poke around the websites of some editors and see who appeals to you (and seems to work within your genre). Then contact them by whatever method they request (often a contact form on their site).

I've done four covers through Ebook Launch for two different series, and they've knocked it out of the park every time. In one case they were creating brand new covers based on a high-concept mashup idea. In another, they were following in the footsteps of a different designer, who'd already established the look for an existing series. Both times -- whether coming up with something totally new or sticking to an established style -- they did fantastic work. I love my Ebook Launch covers!

And a word of warning. The Editorial Freelancers Association, mentioned in this article as a potential source for finding an editor, does not vet its applicants. Anyone, including “self-proclaimed” editors, can join. As stated in the membership guidelines: “Any full- or part-time freelancer may join EFA.” It is basically a listing of freelancers offering services online, and for a fee, members can have access to a job board. While some legitimate editors list themselves on the EFA, so do a lot of other people. Membership is by no means evidence of professional qualifications.
When you get that email, particularly if it's your first book, make sure you are well-rested and in a positive frame of mind before you open it. If it’s your first book, the editing process will be hard on your ego, but remember, the editor’s job is to make your book better and help you learn the craft. You are paying for them to give you critical feedback, not to pat you on the back and say ‘good job.'
I used Ebook Launch to format my first book, a novella entitled His or Her Betrayal for both ebook and print, and I was happy with my results. They are very professional and get the work done in the amount of time that they tell you. I just submitted my second book Love, Lies and Heartbreak, which is a collection of short-stories for them to format for print and ebook as well. I'm sure I won't be disappointed in their work. They are my permanent source for formatting my books. Thanks so much for your great work guys!!
ROUND TWO: an in-depth, comprehensive, line-edit that includes rewriting sentences, improving word choice, organization, plotting and pacing. We’ll make the dialogue stronger and more believable, the action more tense and nail-biting, and the emotional peaks less melodramatic and cheesy. For non-fiction, we’ll strengthen your argument and make the writing more engaging.
I implemented this way of working years ago and see how empowering it is for authors, and helpful for editors to boot. This doesn’t mean you’re asking your editor to do a free sample edit. (I discourage editors from doing this and caution authors who push for it as asking editors to work for free before you hire them may result in resentment.) Paying an editor for a few hours of their time to ascertain whether they’re a good fit for you is a great way to put your toe in the pond before submerging yourself. You can then see for yourself if the editor’s suggestions and comments resonate before moving forward with the whole project.
I have over 30 years' experience in the publishing/writing industry, working as everything from an in-house editor to an investigative reporter to a novelist to a medical/technical writer to a screenwriter. I've been an independent contractor for 24 years working as a freelance editor (developmental and line editing), writer (fiction and nonfiction), ghostwriter, and copy editor.
Every author must decide what is important to him or her in an editor, but in these days of electronic communication, honestly I do not think it is important to seek a local editor unless your book is specifically related to something of local interest. Even in that case, you may benefit from the perspective of someone who does not have all the local knowledge it can be easy to presume, so that you can prepare your book for a wider audience.