Depends on what you are wanna do. Most of us seen a need for something and went for it. Me, I seen that there were people messing up clutch covers trying to do the oil cooler mod. I purchased an extra one and gave it a shot, found out Im pretty good at hitting the oil galley. Decided to mod my original cover and sold the extra one I bought. In the middle of that I had requests to do one for someone else. The scoops no one makes for a warrior and I wanted a pair, made a set and decided to advertise since I can do them so easy.
Duneracerweston seen a need for a good case saver, made a prototype and thats how he started. Obviously he has expanded from that, but that one piece started him testing.
87warrior917 likes aftermarket swingers, thought he could biuld them cheaper than the big companys. Made prototype and low and behold it was cheaper and even lighter than the lonestar he had.