After leaving New York City Ballet to pursue a writing career, McDonagh taught film as an adjunct professor at Hunter College and Brooklyn College, during which time she completed Filmmaking on the Fringe: The Good, The Bad, and the Deviant Directors and The 50 Most Erotic Films of All Time. Her freelance work during this period included film pieces for The New York Times. She became senior movie editor of the TV Guide website in 1995, while continuing to contribute essays to such anthologies as the British Film Institute's The BFI Companion to Horror (Cassell, 1996), Fantasy Females (Stray Cat Publishing, 2000), Zombie (Stray Cat Publishing, 2000), and The Last Great American Picture Show (Amsterdam University Press, 2004), as well as to numerous film guides. Her book Movie Lust, third in the Sasquatch Books series begun with Book Lust by Nancy Pearl and Music Lust by Nic Harcourt, was published August 28, 2006. Later that year, she became the founding vice-president of the Alliance of Women Film Journalists. As of 2008, McDonagh writes the twice-weekly blog FlickChick, answering readers' movie questions on Thursdays and recommending DVDs and giving book-club-style discussion points on her "DVD Tuesdays".