This manual is a compilation of the knowledge, skills, and lessons learned by the Thailand Policy Lab team over the past four years. It incorporates research, global policy lab collaborations, the adaptation of widely used analytical tools from other fields into policy design, the development of policy innovation tools tailored for policymakers, and the creation of TPLab-style policy innovations. More than just a record of knowledge and successes, this manual captures the real-world experiences and challenges encountered in policy experimentation—the successes, setbacks, and the lessons learned. It serves as a resource for policymakers, academics, government officials, and civil society actors involved in Thailand’s public policy process, offering insights to help avoid common pitfalls and work together to improve the nation’s policy framework.