The preppy white button-up got quite a bit of play on the Proenza Schouler fall runway, layered under everything from low-cut vests and crew-neck sweaters to a tightly belted leather bustier dress. The long-sleeved variety of this wardrobe standby has been a trusty go-to piece this winter, but buying a sleeveless one that can work for both cool and warm-weather looks is such a no-brainer. Slip it under a cardigan on a brisk day or use it as the foundation for an arm-baring outfit. For half the shirt, you get twice the options! Can't wait until Proenza releases their version? Opt for a cheap thrill with this $16.50 shirt from Old Navy. We can already tell it's going to be a staple in our spring style arsenal.