computer-aided design
Many different methods, depending on personal tastes, are possible to use in order to visualize an idea. From hand-drawings to renderings, from technical drawings to photo-collages, whatever is necessary to make a project understandable for other people.
It was very intersting to get an overview of the different CAD-programs, from open source to commercial products. Nevertheless my favourite product so far is Rhino, it has many possibilities to be extended with plugins of all kind. The most powerful being grasshopper, allowing to design parametrically.
The amount and quality of open source CAD-programs is fascinating and empowering people, already from a young age, to get in touch with easy to use software and, with a fablab near by, to not only visualize their ideas but also make them become reality.
