Concept inventories (CIs) allow researchers and practitioners to measure student conceptual learning within a course or topic area. While they have enabled meaningful pedagogical change in other disciplines, there are relatively few CIs in computer science. In this paper, we report on our experiences as recent developers of a CI for basic data structures. We discuss each step along the route to a CI and offer tips based on what we have learned. We encourage others to create CIs, and we hope that this paper will serve as a practical guide through the process.