You should be able to find everything you need for this project laying around your house:
-An initial concept and the ability to execute it in a digital format capable of exporting to a 3d printer
-a high res 3d printer
-an injection molder
-a handful of pelletized thermoplastic
Step 1: Part design
I used solidworks to extruded the shape in two directions with 7 degrees of draft on both sides from the parting line.
the final part came in at a volume of 0.238268398 ounces.