This policy paper emphasizes the importance of engaging young people in designing environmental education to promote active and democratic environmental citizenship. It highlights the benefits of co-creation, where youth contribute to curriculum development, making education more relevant and impactful. The paper shares insights from the GreenSCENT Youth Design Assemblies, showcasing successful youth involvement in shaping sustainability education. It also recommends policy measures to support student-centered methods and provides guidelines for organizing inclusive youth assemblies to enhance engagement and inspire meaningful action.