This article illustrates how design thinking can structure the development process of a practical toolkit for schools to address cyber mistreatment from pupils, parents, and other parties as a workplace issue. The process included an exploratory phase to identify gaps in schools' understanding and handling, followed by iterative generative and evaluative phases. Based on the Psychosocial Safety Climate framework, necessary organizational capacities were defined. Prototypes of toolkit components, including vignette videos for discussions among staff, a text guide for policy and infrastructure development, and an informative video, were refined through stakeholder feedback. A summative evaluation confirmed the usefulness of these resources for engaging staff and fostering discussions on cyber mistreatment. A themed webpage was created for free access to the toolkit. This study contributes to existing debates on how academic research can impact practice by emphasizing the usefulness of design thinking in creating innovative, user-centered solutions for capacity development.