1. Always be nice to your editor. Be nice to everyone but always be nice to your editor. They are there to help you, even if they do sometimes make you miserable.
2. They are nitpicking and marking things because they care about their jobs and your story. A good editor wants it to be great. Don't throw that away.
3. But the story is still absolutely yours. If the edit feels wrong for the story or your character, nicely let the editor know that.
4. Edits, for the most part, are suggestions. Feel free to take them or leave them as you see fit. But they are a reflection of how one person could read your story.
5. Edits can be brutal but you never have to tolerate abuse. If an editor is belittling you, calling you names, and generally being a jerk, let the editing director of the publisher know. Or, if you hired them yourself, have an honest discussion with them. They still need to be paid but you don't have to take that kind of treatment.
6. An editor is there to help your story grow, not to write it for you. Massive, sweeping changes that seriously affect your story line should always be taken with a grain of salt. You know your story best. Go with your gut.
7. Never trust an editor that finds nothing wrong with your story. They didn't read it.
8. Some editors are also authors and they may try to change the story to how they would have written it. If their edits make sense, feel free to incorporate them. But unless you're willing to split royalties with them don't start going into too much of their wants and desires.
9. A good editor will tell you when you get lazy. We all do it. If your editor is in love with your work that's fine but make sure they respect you enough to tell you when something isn't right. You don't want to find that out in reviews after the book is out.
10. Make a list of house rules for each publisher you're with. Pubs differ and so do editors within pubs. No one has the same rules but if you're with the same editor a lot you'll know what to look for ahead of time to make their jobs easier.
11. Make a list of your commonly used words. That, though, like, very, etc. Again, your editor will point these out for you if they find them but not having them to begin with will make the editor's job easier.
12. Editors don't get paid much. Be nice to them. They work hard to make your story better. Good cover art, good story, good editing is what you need. Don't skimp on any one part.
13. Making friends with your editors is fine but never forget that writing is a business and they are there for your story and the publisher. Don't take a criticism personally. Respect them, they respect you, your story will come out better for it.