Prototyping, when it’s done right, is always a matter of starting from scratch. It’s about cobbling things together from materials at hand and boldly going into the unknown. This was especially so for Sara Blakely before she founded Spanx. With no experience in the garment industry, she needed to figure out how and whether her idea for sheer, hosiery-based undergarments could work. Her successful, and in many ways prototypical experience offers a readymade guide to the prototyping process.Obsess over every detailWhenever possible, take a do-it-yourself approach. Use everyday materials to build early prototypes. Seek professional help when you know what you want to create but have reached the limits of your abilities.Explain to your manufacturer what you like about existing products on the market. Help them help you. Be specific about how these components inform what you want to create.Gather your own impressions first. Test early prototypes yourself in real world situations. Then,...