In the summer there is nothing better than simplicity. Salads thrown together with farm fresh ingredients, an outdoor table set with mixed dinnerware, and a wardrobe of easy woven cottons and linens paired with classic denim. Denim is showing up in just about every category this season, from dresses and pencil skirts to cropped trousers and pastel shorts. This week’s denim must-have? The vest. It takes your favorite summer dress up a few notches as soon as you slip it on. Can you guess which of these vests is under $30?