Whether you're a pantser or a plotter, a short story pro or a novelist, it's an unfortunate truth that you will need to edit your work at some stage. You might be lucky and work with a publisher who will assign an editor to you, or you might be editing your own work for self-publication, but either way, it needs to be done. It goes without saying that you need to find a good editor, so check out their credentials, ask around, and look to see who else they've worked with. In the meantime, hopefully these five handy hints will help you on your way!
Getting your spouse or your mother to read your work is not editing.
In much the same way that a spouse or friend makes a less than helpful critique partner, unless they're qualified or have experience, then they also don't make good editors. They don't want to pull your work apart, because they've more than likely seen how much effort went into it, and they won't necessarily know either how to articulate the flaw if there's something wrong with it, or how to suggest that you fix it. Best way? Get an editor.
Self-editing is a good idea even if you already have an editor.
There are plenty of guides available for self-editing, and while I wouldn't recommend it's the only method of editing you use because you're too close to your own work, it's always a good idea to self-edit before you send it anywhere. If you've removed typos, massaged out the story kinks, cut back on the purple prose and omitted the repetition, then any editor you hire will thank you for it. It should also cut their workload, thus cutting down what you need to pay them to do.
Listen to your editor.
You are perfectly entitled to ignore any suggested changes, although if you do, question why it is that you disagree. Is it because you don't want to cut a passage that you're a bit in love with, or is it because the editor didn't really 'get' that character? If it's the former, then cut it and paste it into a separate document in case you need it later. After all, Stephen King always talks about the need to "kill your darlings". Writing should be there because it needs to be there, not just because you like it. However, if it's the latter, then if the editor didn't get the character, a reader might not either. Maybe you need to write more passages that fully explain the character.
Don't make changes immediately.
Read the changes that have been suggested, and think about them for a few days, but don't act on them immediately. You may be tempted by the knee jerk reaction of "That's not fair, I'm not changing that", or likewise you might change something that didn't need to be changed, if only you'd thought about it. Give it a few days for the suggestions to sink in, and come back to it when you're feeling a little more objective.
Don't take editing personally.
An editor is doing their job because they want your story to be the best story it can possibly be. They can't do that if they don't point out the weak points. Think of an editor like an interior designer - you've built the house, but they're coming in to make sure it's comfortable and welcoming, somewhere that a reader will want to spend a considerable amount of time. They aren't tearing your work apart, they're trying to improve it. So listen to your editor.