Creative design activities often entails a range of different design materials. We investigate the functions various design materials serve as for example cognitive support and externalisation in both design team practice and individual practice. Throughout the project, we have studied professional designers’ use of post-it notes during different design project activities such as ideation, brainstorming and concept development. To understand how selected creativity constraints affect fluency, collaboration and initiative taking, we set up qualitative studies where high school students from Ørestad Gymnasium and Viby Gymnasium engaged in creative LEGO building tasks with different levels of constraints. We studied groups building with both traditional plastic bricks and using a digital environment. These studies inform the development of creative abilities in a classroom context. One analysis explored how co-designing in the same physical space may affect the design process. Specifically, we explored whether intruding on another designer’s physical space could inadvertently affect team micro-conflicts in collaborative designing. Another ongoing research project also concerns students’ creative abilities relate to the LEGO Duck Challenge, a time-constrained build task involving building different ducks with six bricks. Here we explore how constraints and fluency, related to LEGO, is linked to divergent creative thinking.