Get a separate proofreader after the copy edit

Professional proofreaders are there to catch the author and copy editor’s mistakes. Some copyeditors also offer proofreading services, but it’s often best to get a fresh pair of eyes for that task. If a copyeditor misses a mistake the first time around (no editor is 100% infallible), there’s every chance they’ll miss it during the proofread. If you can, hire a separate copy editor and proofreader.