A coat- look for a coat that is well-made and chic. I liked this neutral one, because it really showcases the dress.
Shoes- if you are going to invest in shoes, go for a timeless option like these nude pumps. As with the neutral coat, it allows the dress to be the focus.
A statement bag- think lush and glam, like this Tambonita statement piece. If there is a season for fab bags, fall is it! Skip basic black and go for burgundy or navy!