I typical wear the following when its below 20 degrees (from first to last layer):
Top: Thin poly baselayer (UA, military, etc), Med weight fleece 1/4 zip shirt, Heavy fleece jacket, primaloft vest, wooltimate jacket
Pants: Thin poly baselayer (UA, military, etc), Mid weight poly/fleece thermals, cheap camo pants, wooltimate pants
Shoes: 1200 gram old crappy rocky boots, Icebreakers boot blankets (add chemical warmers if you want to be toasty!)
Head: baseball cap under a beanie hat, neck gaiter, solid facemask
Hands: Thin gloves, hand muff with 4 handwarmers
Seems like a lot when I write it all down, but it does keep me warm at 0 degrees and 10-15 mph wind like last weekend!