This position paper proposes a model for choosing how to communicate heuristics in a meaningful, usable and accessible manner. The model is a matrix of nine shapes, where we define ‘shape’ as a combination of the heuristic’s format and its directiveness. Examining heuristics used in UX and software testing practices, we found a variety of formats and levels of directiveness. We discuss these shapes with example heuristics from UX, software testing, and everyday life. We present the outcome from a pilot of the model in one specific context. The shape of a heuristic may contribute to its understandability and usefulness in specific contexts, while different contexts may necessitate different ways of communicating heuristics. This includes considering the effect that the shape of a heuristic has on its accessibility and inclusion, suggesting that shape may be one important aspect of heuristics’ design and evaluation.