When engaged in design activity, what does a designer think about? And how does she draw on disciplinary knowledge, precedent, and other strategies in her design process in order to imagine new possible futures? In this paper, we explore Design Heuristics as a form of intermediate-level knowledge that may explain how designers build on existing knowledge of “design moves”—non-deterministic, generative strategies or heuristics—during conceptual design activity. We describe a set of relationships between disciplinary training and the acquisition of such heuristics, and postulate how design students might accelerate their development of expertise. We conclude with implications for future research on the development of expertise, and the ways in which methods such as Design Heuristics can enhance this developmental process.