Background: Patient and public involvement and engagement (PPIE) in healthcare research is crucial for effectively addressing patients' needs and setting appropriate research priorities. However, there is a lack of awareness and adequate methods for practicing PPIE, especially for vulnerable groups like childhood cancer survivors. Aims: This project aimed to develop and evaluate engagement methods to actively involve pediatric oncological patients, survivors, and their caregivers in developing relevant research questions and practical study designs. Methods and Results: An interdisciplinary working group recruited n = 16 childhood cancer survivors and their caregivers to work through the entire process of developing a research question and a practicable study design. A systematic literature review was conducted to gather adequate PPIE methods which were then applied and evaluated in a series of three workshop modules, each lasting 1.5 days. The applied methods were continuously evaluated, while a monitoring group oversaw the project and continuously developed and adapted additional methods. The participants rated the different methods with varying scores. Over the workshop series, the participants successfully developed a research question, devised an intervention, and designed a study to evaluate their project. They also reported increased expertise in PPIE and research knowledge compared to the baseline. The project resulted in a practical toolbox for future research, encompassing the final workshop structure, evaluated methods and materials, guiding principles, and general recommendations. Conclusion: These findings demonstrate that with a diverse set of effective methods and flexible support, actively involving patients, survivors, and caregivers can uncover patients' unmet disease-related needs and generate practical solutions apt for scientific evaluation. The resulting toolbox, filled with evaluated and adaptable methods (workbook, Supplement 1 and 2), equips future scientists with the necessary resources to successfully perform PPIE in the development of health care research projects that effectively integrate patients' perspectives and address actual cancer-related needs. This integration of PPIE practices has the potential to enhance the quality and relevance of health research and care, as well as to increase patient empowerment leading to sustainable improvements in patients' quality of life.