Step 1: First learn how to build things with your hands
Step 2: Invent a product
For example, My product, the Hard drive zapper was a solution to the problem of getting scrap computers for my company. Businesses and schools refused to sell me obsolete computers without some type of data security. I put together the Hard Drive Zapper as a simple cheap and relatively secure solution. Although it is not as secure as a several other data destruction methods, it is secure enough for the average homeowner who just wants some peace of mind while disposing of a computer. i have made this fact clear to all of my customers.
Step 3: Design a method for manufacturing
For Example It took me over 4 Hours to build the first zapper. After optimizing my design, i reduced the time down to 3 minutes when built by a mentally retarded person.
Initially I built a bunch of zappers and recorded all the steps i went through. then i timed each motion. Using flow charts and gant charts i tried to find and eliminate the slower steps in construction. I optimized production by reducing multiple actions into 1 swift motion. I also built tools and machines like a small plastic extruder and crude injection molds to help speed up production. Unfortunately i failed to finish everything when i left for college so my extruder and more complex machines are on hold till Christmas.