For stand huntingin temps well below freezing:

Base layer: Microfleece longjohns
Mid layers: heavy wool shirt andwool or fleece vest
Outer layers: KOM wool jacket, heavy wool surplus pants,fleece neck gaiter, heavythinsulate watch cap, and glove-mitts

For stand hunting in brutalzero/minus-zerotemps (rarely), I'll add loose polarfleece pants, apolarfleece jacket, and a fleece balaclava to the works.

For short after work hunts and especially for stillhunting, I wear much less or I'd sweat to death!