Writing-to-learn involves the use of low-stakes informal writing activities intended to help students reflect on concepts or ideas presented in a course. Writing-to-learn can be a flexible and effective tool to help students understand and engage with course concepts, and past research has shown that writing-to-learn activities can substantially improve performance on summative assessments. Not only is coherent writing helpful for learning, it is also a skill that students are expected to acquire during their degree. However, it can be a challenge to provide writing opportunities that are both interesting to students and easy for instructors to implement and grade, particularly in courses with a large number of students. Reflective journaling is one method that can address these learning objectives. The versatility of reflective writing means that it can be adapted to suit a number of different disciplines. In this essay, we will explore reflective writing as a subgenre of writing-to-learn activities, summarizing some of the benefits associated with these assignments that have been described in the pedagogical literature. We will then describe how to tailor the assignments to different kinds of disciplines, including STEM courses, professional programs, and the social sciences and humanities. We will provide some guidance on how to resolve tension around marking and feedback for such an assignment. Finally, we will describe our individual experiences with using this kind of assignment in two courses. As there were a number of contextual differences between the two courses, including size and discipline, our commentary is advanced within the specific context supplied by each.