This chapter explores the value, impact, and best practice of patient and public involvement and engagement (PPIE) in health service evaluations, with a focused look at the challenges in commissioned evaluations. Taking a solution-focused approach, the chapter provides examples of evidence-based responses to challenges around offering inclusive opportunities, working together in a meaningful way, and capturing the impact of engagement, along with top tips for being involvement-ready. The chapter does not assume prior knowledge and will be of interest to those who are new to public involvement and those who are interested in reflecting on their practice or trying new approaches. Quotes from patients and carers who collaborate with us in our research and teaching are woven throughout the chapter to share their voices.