Above all don't get caught in a winter drizzle wearing a cotton t-shirt. These fabrics are available as jerseys, tights, socks, gloves, and outer shells and will offer many of the best traits of natural wool without suffering it's weight penalty. For the feet, start with thin polypropylene liner socks. These really wick moisture away from the skin. Cover the liner socks with a mid-weight wool sock like the SmartWool socks now found in bike shops.
Shoes are next.
Instead try putting some neoprene shoe covers over your shoes to add insulation and fend off the mud and water. T o keep the feeling in your hands, start with a Thermax or Thermostat liner glove. These liner gloves have amazing wicking and insulating characteristics. Cover them with a mid-weight Thermax, neoprene, or Thinsulate filled outer glove. The Thermax mid-weights are good for milder temperatures.