This week I have been digging deeper into my inventory of cold weather gear. (Disclaimer: I don't have any tips on keeping costs low. I have invested plenty of money in my cycling wardrobe.)

• "Cotton Kills." The problem with cotton is that once it gets moist, it saps the body's heat and you will become hypothermic quickly. It also becomes abrasive and causes blisters.
• Wool is versatile and does not itch if you have Merino wool, which has undergone a revolution in the manufacture process and is very soft and comfortable. It can maintain your body temperature, even when wet. It does not smell if you need to wear it multiple days between washings. It does not need to be hand-washed. It is not cheap.
• Base layer. This is the layer against your skin. don't pick cotton, but your choice should be thin so it can wick moisture away. Generally a micro-fiber, such as polyester. I prefer a short sleeve base layer. 
• Layers. On top of your base layer will be your long-sleeve jersey. Consider the zipper your thermostat. Each layer other than the base layer has a zipper, which you generally will be adjusting whenever you are too warm or too cool. 
• Vest. Wind vest vs. thermal vest. Did you ever notice that cycling vests and jackets can be zipped from either the bottom or the top? There is a reason for this. In order to be able to reach your jersey pockets you unzip from the bottom up. 
• Jacket will be chosen depending on the conditions. My favorite winter conditions are when there is cloud cover that never burns off and the temp is consistent for the whole ride. When the sun comes out, it complicates things. You have to stop and peel layers off and stow them away. See my blog on how to carry stuff. 
• Socks. Wool! Most people still need some extra protection to keep their toes warm. You can get toe covers, which are fine for many folks. I prefer shoe covers that cover the entire shoe and ankles. These come in light and heavy varieties. Some are easier than others to get on and take off. 
• Tights, I don't use a base layer for the legs, just one layer. I have three different pairs of tights that I use depending on the temperature. Knee warmers are useful when it it is not quite cold enough for tights. 
• Fingers. I have three weights of gloves and use them all depending on conditions. I also have lobster gloves, which I have only used once, descending from the Ancient Bristle Cone Pine Forest in the White Mountains during a snow storm.   
• Cap. My favorite cap is a thin polyester version that can cover the ears. I have a nice wool cap and I have some ear covers that attach by velcro to my helmet straps. A balaclava can be used when you need to protect your face as it covers the entire head.