This year I opted for a fleece neck gaiter and a matching cap rather than balaclava for cold weather. It seems more comfortable to me, and adjustable. Down to mid 30s I wear a cap and earmuffs (my ears are sensitive to cold wind), Low 30s to few degrees below freezing I wear a thin balaclava under the cap. Lower 20s, used to be a thick balaclava but now it's the gaiter and a cap.

On the bottom, Pearl Izumi Amfib bibs below 40F with shorts over them or fleece-lined work or hiking pants over the bibs below 32F. I like the bibs since they protect your back nicely in cold weather. I'm thinking about getting fleece-lined work overalls.

In the middle two thin Merino wool base layers, merino wool sweater and variety of Columbia or Nautica hiking/outdoor jackets depending on the temperature, nothing really bike specific.