Kate Middleton Nailed Elegant and Sexy With This 1 Perfect Dress

We're used to seeing the duchess in pretty sheath dresses and fascinators, but when Kate Middleton throws on an evening gown, she looks exactly like a modern-day princess. At Thursday evening's reception for the 40th anniversary of SportsAid, an organization that helps to fund the careers of young athletes, Kate proved our point in an appropriately royal blue Roland Mouret gown. The elegant look stayed true to Kate's classic aesthetic, though you'll notice one trendy twist.

With cutout shoulders, it's a dress that touches on one of Spring and Summer's biggest runway looks, adding a sexier finish to an otherwise more conservative gown. So, while we're always taking notes from Kate's carefully selected wardrobe, we're tuning in specifically to this and, namely, how to look for small details that set a classic look apart from rest. Not that Kate has any trouble getting noticed. Read on to see how she elegantly mastered eveningwear once again, adding glamorous hoop earrings and a minaudière. Then, take her brilliant style cues and shop.