Virtual designs into physical objects/Get your hands dirty
Craft the item yourself or in a group according to plans using your own skills and tools plus readily available 'off-the-shelf' components. Lo-tech but effective. Step-by-step 'how-to' guides, sometimes with video, are increasingly being published on the internet for this kind of project. See Instructables as a good example.
Or someones else's...
Small-scale local engineering firms that will make custom items to order have always been around, often specialising certain materials and techniques.