Not that the ASJ is a "normal" shape, but still.
So, I tried to do Elizabeth Zimmerman's Baby Surprise Jacket [Rav link]. That went much, much better!
I was originally just going to knit it in green yarn leftover from my Enlightened Hoodie, but added some black.
Then it was a case of figuring out how to fold the thing: Figure A isn't it. It does, however, give a good idea of how the stripes will work. The cast-on edge is at the top of the photo, the final cast-off edge is at the bottom. You can see where I put the stripes:
Now, in Figure B, you can see how those same stripes are placed in the finished jacket. (And yes, the "surprise" is that this weird amoeba-yarn-thing actually folds into a jacket.) My first stripe started at what wound up being around the armpits.
I did add some stuff to the finished jacket: knitted buttons (knit a square. Run yarn around the whole edge, pull tight. Instant button!) and a collar.
I think it came out pretty great!