Understanding injection molding is great advise but it’s still financially not easily accessible. The gateway drug into mold making that you can actually do now is buy one of these affordable mold making starter kits Link below. My site and my Instagram has examples of custom molds I made for botshots characters using injection molding smoothon. I made a trailer for ultramagnus. in combination with 3d printing to make your master mold you can make almost anything. Below are some pictures. Kits, Everything You Need To Make It Now!