Vests can be excellent mix-and-match wardrobe pieces. Rather than limiting their use to the three-piece suit, use vests as coordinating pieces for sport coats and trousers. Consider having vests personalized to your taste—lapels, pockets, fabric, and fit can all be custom-crafted to create timeless pieces that will give you extra options with your existing shirts, trousers, and coats.
Traditionally, vests are made of the same fabric as a jacket or trousers. They can also draw on contrasting colors, or simply use a base color from the jacket or trousers. When creating combinations, keep fabric choices (tweed, silk, cotton, wool) similar enough to avoid an awkward pairing.