Sewing class has totally been kicking my butt. I have also discovered that my imagination greatly exceeds my skill. So.
Lesson 1: if you are not a very good patternmaker / drafter yet, drape the damn thing.
After putting the tuck into my first flat pattern-generated muslin, I decided that I didn’t like how the colorblock angle was not so steep anymore. So I draped instead, made a new pattern, sewed a new muslin, and added short sleeves. Time sink.

Lesson 2: if you are not a very good seamstress yet, don’t use silk charmeuse. Corollary: charmeuse is the dumbest material to use for geometric designs.
It turns out that silk charmeuse is almost impossible to get looking crisp, which is problematic when that’s the whole point of your design with clean colorblocked lines. Next time, cotton (and it’s much cheaper). Also, the bias was a LOT more stretchy than the cotton muslin I was using, so now it has this ripply hem that makes the bottom of the middle triangle kick out. It looks so stupid.
I am really annoyed at how sloppy it looks. But it’s done. Pictures and construction details will come when I am less annoyed. And when the coat is done.

Here is the mess that used to be the dining room. One good thing is that I watched the entire kdrama Who Are You while working on this thing. Fun.