A thin layer top and bottom like silk long underwear I also really like snow angel stuff but it's pricey.
A medium layer on top (light weight polar fleece) I like the stuff that has a zip up high neck.
A polar fleece vest can be nice.
A down vest really keeps you warm (if it is dry out and not too windy)
I prefer shell jackets with zip in (or out) liners. Very versatile.
In Ca, a down "sweater" might also fill the bill- down is super super warm.
Patagonia expedition weight long underwear (polar fleece) is quite warm- it's a little bulky but can be worn under shell pants.
A hat or at least an ear band
gloves
Warm socks like smart wool.
Sierra trading post has great deals.