Although graduate schools provide some opportunities for students to learn teaching strategies and methods, opportunities to practice remain few. Furthermore, practice alone is insufficient, as reflection serves a key role in developing teaching skills and requires purposeful, persistent, and deep thinking about experiences. However, graduate students, with limited time and competing priorities, typically focus on strengthening discipline-specific knowledge and skills, seldom taking time to reflect on teaching experiences. Lacking foundational knowledge for effective teaching, these graduate students may be uncompetitive in pursuing academic careers. This study investigated graduate student perception of teaching development during a college teaching course. Related to how graduate student teaching developed, major findings comprised increased teaching confidence, a developed teaching philosophy, and an applied course design cycle. Specific to the latter, participants demonstrated course learning outcomes, assessment, learning activities, and alignment of the aforementioned syllabus design as well as analyzed and proposed future action based on the teaching experience. Related to why graduate student teaching developed, major findings comprised instructional course design elements, specifically course content and graduate student teaching preparation, multiple teaching experiences, and reflection on their teaching, especially instructor, peer, and video feedback.