I absolutely love this shirt dress. The gold buttons down the front and the belt are the perfect details for fall. Metallics have been trendy all year, but trying to keep them seasonally appropriate can be difficult. For Spring, I like to go with lighter metallics like silver. Summer...a little more bold with brassy gold and rose gold as well. Mixed metals work well in the Summer too. Then for Fall and Winter, dark metals like gunmetal, steel and darker gold.
In terms of a night out, a clutch or wristlet is always appropriate. This is where you can bring in a bold pop of color, like this incredible crimson. Invest in a few strong clutches for your evening events, and you will be all set!
The only other thing that I might add would be an overcoat of some kind, likely a motorcycle jacket with an asymmetrical zipper, or something in a dark denim with the cuffs rolled up. Since the dress has a definite style, I would stay away from a trench or anything belted as I likely wouldn't do up the jacket...it's really just another piece for layering!