This paper documents efforts to implement portfolio assessment projects at Bank Street College (New York), with a larger goal of fostering reflective practice among student teachers. The use of portfolios was adopted as an alternative option for students' culminating projects, and was found to mesh well with the college's institutional and pedagogical goals. The decision to require an articulated theme that would run throughout a student's portfolio materials is discussed, including ways in which use of portfolio themes limited some students' ability to collect sufficient, relevant, and high-quality materials. Choosing themes early on and remaining flexible to changing themes are suggested as solutions to this problem. While portfolio mentors and other forms of faculty support and consultation were made available, most students did not utilize these options and regretted it later; as a result, such consultation was made mandatory for later cohorts. In general, it is argued that new pedagogies are most effective in encouraging reflective practice when they deepen and extend forms of reflective teaching already existing within the institution. (Contains 19 references.) (PB)