Citizen science (CS) projects have become widespread in part because they expand the capacity of professional scientists, enabling research that would otherwise be impracticable or unaffordable. In addition to the research benefits, educators and scientists have seen educational value in CS because it can incorporate students into real-world science projects. As a result, CS is increasingly making its way into schools. This report offers experience-based insights that can help realize the promise of school-based CS. All of the authors are scientists who have been involved in such efforts.