This article examines the experiences of advanced students and of graduates in a nontraditional MA in professional writing program to discover how faculty may assure student success in professional writing occupations. The study investigates the knowledge domains and habits of mind that foster student success in writing. The research is the collaborative effort of three rhetoric and composition specialists. Their research discovered that successful writers (1) define success as gaining a response from readers; (2) master six knowledge domains--genre, writing process, rhetorical, subject matter, discourse community, and metacognitive knowledge; (3) put their knowledge into action through eight similar habits of mind--persevering, embracing learning, attempting challenges, responding positively to critique, engaging in collaboration, understanding how to write in complicated contexts, and engaging in metacognition; and (4) acquire these abilities from a range of personal, professional, and academic experiences.