Always, always, always, put your name and your contact information on your manuscripts.
A manuscript scheduled for publication in one of the periodicals I edit had become separated from its cover letter, if there ever was a cover letter, between the time the manuscript was scheduled for publication and the time it actually entered production. I spent a good bit of time Wednesday attempting to track down the author. Only some creative use of Google led me to the person I think is the author, and a brief letter went into the mail because I could not find any Web site or e-mail address for her.
If I guessed wrong, or if the author doesn't respond promptly, this sale may be lost.
Why do so many writers fail to include this information on their manuscripts? Why do they set themselves up for failure? Why do I continue to beat my head against this brick wall when other writers' failures only make my submissions appear even more professional by comparison?