My most complex “from scratch” design so far–My own pendant lamp! It’s sized to fit the hanging bulb thingies from Ikea. I’m too lazy to go look up the catalog number right now, sorry!
I’m including a photo of the 3/4 scale cardboard prototype, because the real one doesn’t have all its fins yet (I had to stop and help Gkid with creating a sign for her bedroom). Also, the fins it does have are kind of an eclectic mix (I have a hard time making decisions

Obligatory American consumer warning: Those top points are SHARP. If you fumble and cut yourself I’m not accepting responsibility, so take proper precautions. Or file them. Or something.
Also, you’ll have to remove fins to replace the bulb. I like how the fins nearly meet at the bottom. So leave a couple unglued, if you’re the “glue it together” sort.
Here’s the SVG: