Don't assume that a blazer has to be worn with a shirt and tie. Don't get us wrong, you can roll with that look, but for the sake of keeping toasty, you'll want to layer up. Try a quilted vest underneath your blazer to kick around in on the weekends. Or grab a light, technical jacket and wear it over your blazer. A denim jacket is also fair game and will be best if it's washed or actually vintage. If you really want to blow minds, unzip a bomber jacket and wear it under your blazer. This advanced move works best with unstructured blazers made of tweeds or other less formal materials.