I adore this dress, and wore it for my birthday dinner last year. It has everything I love: navy, pleats, Peter-Pan collar, open back, but I have trouble transitioning it to cold weather because adding a cardigan covers up my favorite part.
Oh well. I do love the way it looks a bit schoolgirl-ish layered over navy wool tights with a brown leather belt and matching boots. It's so demure that the open back comes as a bit of a surprise, don't you think?
Open-back dress - Asos (also seen here)
Navy wool tights - online tights shop (also seen here)
Vintage leather-link belt - thrifted (also seen here)
Chevron cardigan - Missoni for Target (also seen here)