How to Revise and Resubmit a Journal Paper

So, you've submitted your paper to your ideal target journal, waited the requisite period, and one day, your inbox contains an e-mail from the publication's editor-in-chief. It's not the hoped for acceptance, but a "Revise and Resubmit." (One of my favorite journals has switched to the more-discouraging, "Reject and Resubmit," but this is actually the same thing.)