The document outlines principles for citizen engagement in co-creating future cities. It summarizes interviews with organizers of citizen engagement initiatives in cities like Aarhus, Santander, London, and Barcelona. 7 draft principles for citizen engagement are described. The principles emphasize empowering communities, designing for trust around change, facilitating ownership, debating across comfort zones, using challenges to drive innovation, choosing the right venues, and providing a clear process and visibility of outcomes. The document also outlines a proposed "Experimentation as a Service" journey from initial awareness and challenges to co-creation, experimentation, and examination over 17 months.