Online courses have become an increasingly common feature of the higher education landscape, expanding access and offering flexibility for students. Yet, they also pose unique challenges. Research has documented concerning performance gaps between students enrolled in face-to-face and online courses, while faculty have reported difficulties promoting student engagement and encouraging strong performance in online environments. In this new brief, the Postsecondary Teaching with Technology Collaborative hears directly from students about their experiences in online courses. The brief examines how students develop and use self-directed learning (SDL) skills--motivational, metacognitive, and applied learning processes that enable them to sustain effort, reflect on progress, set goals, and adapt their study strategies. Drawing on interviews with students in online STEM courses at eight broad-access institutions, the brief reveals key insights into students' strengths, motivations, and learning strategies for online courses. Building on the Collaborative's previous research into SDL, the brief offers evidence-based recommendations for improving online instruction and reducing performance gaps. It emphasizes strategies that support active learning, encourage meaningful instructor-student interactions, and leverage students' existing strengths.