This publication, along with the rest of the publications in the series, is a product of the Juvenile Detention Alternatives Initiative (JDAI) sponsored by the Annie E. Casey Foundation. The project's objectives were to eliminate the unnecessary use of secure detention for juveniles; minimize failures to appear and the incidence of delinquent behavior; redirect public finances from building new facility capacity to responsible alternative strategies; and to improve conditions in secure detention facilities. The JDAI has shown that detention systems can change when key policy-level system actors come together and do three things: develop consensus (relying heavily on data) about what is wrong with the system; develop a vision of what the new system should be; and develop and implement a plan of action. In pursuing these three activities seven principles emerged from the successes and failures of the JDAI sites. First, forming a collaborative group for system reform is difficult work and will take longer than anticipated; second, for collaboration to work, all the relevant stakeholders must be at the table; third, in collaborative-driven reforms, the group must develop consensus about what should change and how it should change; fourth, there is no real collaboration without negotiation and willingness to compromise; fifth, without strong and able leaders, reform is unlikely; sixth, collaborative leadership must include a jurisdiction's "movers and shakers;" and seventh, self-assessment and data are essential engines for effective collaboration. In addition to explaining these guiding principles for collaboration, this booklet contains chapters on organizing and sustaining collaboratives, some leadership challenges, and lessons learned from the development of collaboratives in the five sites involved in the JDAI.