One of most vital things to keep you warm during winter is a good hat. I recommend a trapper-style hat that will cover your ears and will tie under your chin to keep the cold air out. They might look a little extreme, but trust me, you won't care once it's cold. Plenty of stores have vegan options (meaning no wool, leather or other animal byproducts). The one pictured is 100% acrylic and from Urban Outfitters. It cost about $40. Other stores that feature good vegan winter hats include Target, REI and GAP.