I've been told that pumpkin juice is a favorite drink of wizards and witches. I haven't tried it myself, but I thought it would be fun to design a lapel pin that looks like a pumpkin juice bottle cap. It's the same size as a real cap, with a 3-D wiggly edge, and the back is even recessed a bit.
I custom-lettered the word "Pumpkin" for a peppy mid-century soda pop look. The pin uses orange hard enamel, in gold or silver metal. 28mm wide (see last photo for size reference). Black rubber clasp.
Also check out my Butterbeer bottle cap pin.