Learning to become a teacher is a developmental process, part of which is learning to become a reflective practitioner. The authors have implemented a structured approach to developing the habits of critical reflection, the purpose of which is to guide their university students (who are pre-service teachers) to progress through the stages of teacher development and to facilitate self-motivated professional growth. Their attempts to incorporate into these pre-service teachers' learning the "practice" part of reflective practice have included the development of different kinds of practical and applied tasks. In turn, their attempts to incorporate the "reflective" part of reflective practice have involved the embedding in assessment activities of different scaffolds for metacognitive reflection. Their innovative processes of embedding reflection in assessment have been guided by Dewey's and Schon's views of reflection, their own views of the teacher education process, and Brookfield's conception of "critical lenses" which can be used as a scaffold to structure professional growth and development.