Buff®Sports | Original Buff® | Skiing
I wear a Buff. They're really breathable and keep you relatively warm. For REALLY cold days I'd get something else. They're thin enough so you can pull the buff up over the bridge of your nose and pull your goggles down over that so you're fully covered. You don't feel suffocated and your goggles won't fog up. Great for days when its snowing and you're getting facialed by flakes.
They're really dynamic too - I turn mine into a beanie when I job outside in the winter.
Cool colors/designs, cheap and super functional. Highly recommended.