Using an autoethnographic approach, this paper reviews and examines how I went through my professional development journey to develop as a curriculum planner and manager by engaging in critical reflective practices to enhance the quality of teaching and learning in the era of Curriculum Reform in Hong Kong. A series of carefully selected critical incidents relating to school-based curriculum development were examined to witness how I approached a brand new primary Social Studies area of study and developed it as a distinct multi-disciplinary school-based curriculum. The curriculum documents, learning and teaching materials, students' work, personal reflective writings as well as personal communications with parents and students were collected for thematic analyses. By reflecting on the critical curriculum development and implementation incidents, a school-based curriculum development model evolved. This helps shed light on how school practitioners, irrespective of their positions or teaching experiences, to engage fruitfully and continually in the professional development process to develop as an effective curriculum developer and manager in schools. The experiences also inform teacher educators as well as school practitioners the salient characteristics and needs for a teacher to grow up as a reflective practitioner. [Copyright of Reflective Practice is the property of Routledge. Full article may be available at the publisher's website: http://dx.doi.org/10.1080/14623943.2015.1023279]