1. Add dark colored tights. The tights can be black, brown, plum, dark red, or any other color that compliments the color of your dress.
2. Wear a blazer or open trench coat over it for a more formal look. It will also keep you warmer!
3. Wear a scarf with your dress! Depending on the style, this might not work. For bright colors, softening it down with a scarf will look great!
4. Closed toed shoes! Oxfords will immediately make your look more autumn-y, and you can even wear riding boots, or something like them, for a more edgy look!
The key is to soften the dress down with accessories that make your look work with the season!