+1 on arm warmers and leg warmers.
Of course my wife and I are riding in North Texas so cold is kind of a relative thing here.
Arm warmers and leg warmers give us the ability to regulate our warming/cooling as we ride. This time of year, an early Saturday morning start can be around 36-40 degrees, by noon, it can be up to 65-70 and sunny. It's nice just being able to shuck out of the warmers and stuff them in a pocket or bag without having to deal with the bulk of a jacket and tights.
Semper Fi