Recently a client asked me to do a sample edit and quote to copyedit his MS, which is a biography of his late grandfather’s career (and exploits) as a senior police officer early last century. When I did a short sample edit (4 pages), I realised there were some pretty major issues with his writing and the structure. So I sent it back with my comments and we discussed doing an MA, which I did. Now he’s working on sections of his MS and then sending them to me (he has poor health so we are doing it in stages). It’s a collaborative effort and we’re enjoying working on it together. If you have a client who is open to working with their editor, their book can become something they are really proud of, and it’s equally satisfying for the editor.
Second, consider getting a critique before you decide whether you need to pay for a full copyedit. I (and probably many other editors) will read your manuscript and write a several-page critique for much less than the cost of a line-by-line edit, and if your mechanical skills are reasonably good, this may be sufficient to help you get it into adequate shape for your publication plans.
Work in house first. That’s the best way to learn all you can about editing and proofreading and make good connections. I have met several people I’ve worked with from hanging out in Twitter and responding to tweets asking for an editor or proofreader, but I have had the most success from business connections I made while working in in house. Other things – a web site, professional associations such as the SFEP and the EFA (though I can’t say much more on these as I am not a member of either yet!), social media.

Fiction writers may want to join a writers group or workshop to benefit from the help of others who have experience with your genre and can help you develop your craft, challenge flaws in your narrative or character development, and help you improve the overall quality of your story. A flawed plot or character is much harder to revise after you finish writing your book, so it’s important to catch such problematic aspects of your book early on.
First, decide whether your time or your money is worth more to you right now. You can greatly reduce the amount of money your project will cost by investing more time, and vice versa. If time is no object, you may want to spend some hours in the library reading style manuals and going through your manuscript with a fine-toothed comb so that when you do hire an editor, (s)he will be able to zip through it quickly. If you end up deciding that’s more effort than you want to invest, then you will at least find the monetary cost of hiring someone to do it for you a less bitter pill to swallow.
Open the book and start turning the pages until you see the title page. Some books will have a single blank page, while some will include marketing materials or quotes. Novels will often list an author’s other books. Turn pages until you find the title page, which will have the book’s title in large letters in the center or upper-portion of the page. Look underneath the author’s name at the bottom to see if there is an editor listed.[1]
Obviously there is a big difference. I actually started with screenplays (with some mild success) partly due to hearing that as long as you have a good story, the grammatical errors won’t be a big deal. Well, that was not true. Maybe if a producer liked the story or I was already established but every contest I entered always came back with feedback about the grammatical errors. Even if I won or placed as a finalist, I always received critique on that. Very little is spelling error, it was more about structure, etc.