We developed principles drawn from empowerment and realist evaluation theories to guide a family youth alcohol and drug program evaluation, before reflecting on our experience to develop additional principles for future work. The research team included the program clinician and an independent researcher. A purposive sample of young people and one parent took part in interviews. The principles we applied include practical and transformative elements: a collaborative, multidisciplinary team; valuing client perspectives; diffusing power; the belief that programs aim to achieve positive results; capacity building; and sharing information for personal benefit. Additional principles were having young people on collaborative research teams, addressing organizational readiness to embed young people's involvement in research, accounting for gatekeepers in recruitment processes, and using information communication technology. While principles should be flexibly applied at project level, they can guide project design and encourage the development of organizational systems that support collaborative inquiry.