I have a poncho, I admit it, a 15 dollar on sale one from U.O. I have only worn it on the ferry (blast of cold when you step out of the car!). But it dwarfs my petite frame, really. So most of the time it is just over my legs in the car (can't have the engine/heat on when the boat is running!).
I do have a cape jacket that I love, the cape part only comes down to the elbows, over the shoulder. It's not very warm because the sleeves are so open, but I love the drama of it. Both of these are in neutrals and I think it can help the look not to be too "little red riding hood", or costumey. Paired with a leather jacket, it can be a nice layering piece too.
It will be fun to see what you make.