My olive military vest is in full rotation. It’s the perfect transition piece, light enough to add layers, but not warmth, and lays nicely over dresses, button downs and blouses. Once it gets a little cooler, it will be perfect for over sweaters as well. If you don’t have one, you should get one, I think you will be surprised at how much you wear it.
A few of my favorites:
Image Credit: Top Left, Top Right, Bottom Left, Bottom Right