In the context of the professionalization processes for aspiring teachers, the promotion and initiation of reflective skills is considered to play a central role. Portfolio work can enhance this reflective competence and is regarded as a professionalization tool within teacher education. Against this backdrop, the book explores implementation scenarios for how effective and cross-phase portfolio work can be designed. In addition to presenting the empirical findings, it provides insights into successful portfolio work and its advisory support through concrete practical examples. Alongside international examples, the focus is on representations of the "Portfolios Practice Elements" embedded in teacher education in North Rhine-Westphalia. The articles are based on contributions from students, trainees, and educators from the first and second phases of training.