The "Boston Teacher Leadership Certificate" program was designed in 2010 to build Boston's teachers to be stronger professional resources for one another, their schools, and district reform. The program's key strategy has been supporting experienced teacher leaders to design and facilitate graduate-level leadership development courses for their peers. To date, more than 100 teacher leaders holding roles such as team leader, content coach, data facilitator, or mentor have participated in this teacher-led professional learning to build the leadership skills needed to be effective in these roles. Program participants completed an online exit slip at the end of every course session. In addition to providing feedback on context, process, and content of each session the exit slips provided an opportunity for participants to think about what might make it easy or hard to put their skills to use in their schools. Analyzing data gathered from the spring 2011 to fall 2012 sessions, program leaders saw clear patterns emerging in the contextual conditions teacher leaders perceived as critical to their effectiveness. Four conditions were evident in their responses: a common vision of shared leadership, clarity around authority, trust, and time. The Boston Teacher Leadership Certificate program leaders used what they learned from teacher leaders to create a series of discussion guides designed to generate productive, focused conversations among school leadership teams, administrators, and teacher leaders together. These guides can support teacher leaders, their principals, and the other leaders with whom they work to discuss and take action toward creating conditions that maximize leadership capacity.