The closer to your skin, the thinner the material. Start with the softest layer and work your way out to the most durable. Begin with a light undershirt, add a top shirt, then build up.
Mix your fabrics, textures and colors. Graphic sweaters or bright colored knits aren't so shocking when they merely peek out from under a jacket. A crewneck sweatshirt is an ideal piece to layer over a shirt and tie, and under a blazer. Wear your beat-up jeans or casual cords with a nice cardigan and some dress shoes. Roll up your sleeves and pop your collar when applicable to showcase the various colors and textures.
Use the inner layers to inject a little color. A yellow scarf, bright blue henley or pink T-shirt is an easy way to brighten up a dark winter wardrobe.
No layer is more easy or versatile than a lightweight vest. They add texture and color without compromising any comfort. Under a blazer, a denim jacket or even a military coat—a quilted vest just works.
The next few months offer a great opportunity to utilize your wardrobe by combining your favorite pieces into something that's comfortable, stylish and most importantly, insulating. After all, when the temperature dips, you're better off wearing two or three thinner layers of clothing rather than one thick one. The genius of good layering is that it means you're always dressed appropriately—even if means peeling off a layer or two when you warm up.