The Create-Build-Test-Learn supports toolbox for engineering concept development motivates not only experimentation, but also instils design thinking in teams. By offering tools and methods for reconstruction of the design challenge, the approach prevents teams to jump into a solution too quickly. When using prototyping as a team resource, reframing of the problem becomes part of the process, ensuring that efforts are put on solving the right problem. The article describes the contents of the toolbox as well as exemplifies how to use it. CBTL has been designed in particular to support SMEs.