I use a compression T as a first upper layer. Wicks sweat and protects the other layers from body oils. Less washing.
A wool watch cap under my helmet stiffles the heat sink that is my head. Usually the first to go.
For the hands, a pair of insulated glooves. I carry a pair of extra large 'chemical protection gloves' as an overlayer in case of rain, and/or as a windbreak for my hands when it's that cold.
My yellow Northface Venture rainsuit is a major component of cold weather riding. Obviously a windbreak, but it 'breathes' nicely, allowing some air flow. This plus one or two upper layers, as needed for the temp, keeps my core warm. Unzip/shed as needed.
Lower layers can be thermals plus jogging pants plus, in extremis, the rain paints. The jogging pants double as off bike garb.
Shoe booties for rain and a couple pair of wool socks completes the packing.
The goal is to minimize the garment count and maximize the protection. My winter gear adds about 4 pounds and a lot of bulk to the clothing pannier when not in use.
Last edited by Cyclebum; 05-28-11 at 05:41 PM.