The purpose of this study is to determine what good coaching during design-based learning (DBL) entails by integrating theoretical and practical perspectives on good coaching. For this purpose, a grounded theory approach was used. For the practical perspective, themes on good coaching were derived from a qualitative study on coaching by observing and interviewing teachers and students involved in a DBL project. For the theoretical perspective, we consulted and analyzed literature on scaffolding, feedback, and formative assessment and coaching in problem-based learning from the learning sciences and the studio model from arts and design literature. Synthesizing themes from both perspectives led to the development of a theoretical coaching model consisting of three main categories (and four subcategories), seventeen themes and thirteen propositions. The model and propositions might be of use for those involved in coaching students in DBL and provide relevant directions for research on coaching in DBL.