This neckline falls right at, or sometimes above, the collarbone, making an updo your best bet. Anything too sexy or casual won't fit with this demure look, so stick to a clean, sophisticated hairstyle. Here, we update the French twist by gathering hair at the crown, twisting down, then wrapping the twist into a neat chignon. Malone gown, $3,995, Karen Hendrix Couture. Sage hairpin, $25, and Triple Pearl hairpins, $10 each, all Tigerlilly, tigerlillyjewelry.com