This article is about a computer lab project in which prospective teachers used Geometer's Sketchpad software to create two-dimensional nets for three-dimensional shapes. Since this software package does not contain ready-made tools for creating non-regular or regular polygons, the students used prior knowledge and geometric facts to create their own custom tools with Sketchpad. Using their handmade customized tools, students created various nets for prisms, pyramids, and the Platonic solids. The author taught nets without this approach and then with this approach, and found not only a positive difference in performance on assessments, but also more excited and engaged attitudes about the material. The pre-service teachers were eager to simulate this activity with their future students as well as use their tools for their own test-making needs.