I have a couple patterns for this style of blouse so I picked one of those: burda 5765 from the 80s. The pattern is plain, and I don't really follow patterns anyways, so I traced it and altered the back to have a tie, shortened it, and made the neckline wider.
I kind of wish I had put in the effort to match the stripes on the shoulders. Bah. I didn't really think about it until it was too late.
The shoulders are French seamed, and the side seams are folded under and stitched down. This stitching is visible on the outside, but the line follows from the "sleeve" hem. All the other edges are bound with a continuous strip of bias binding I made, which as you can see has a lot of rippling happening. I don't really have the proper tools to make binding out of a thin silk like this, so I'm learning to live with it.
Though it's meant to tie in back, the shirt does still kind of work the other way around as a little jacket. Just for fun, here's some photos of that: