Climbing through the forest, wear midweight base layer tights with shell pants, and a midweight top. At tree line in the wind, add a fleece quarter-zip and waterproof/breathable jacket. During breaks, throw a down jacket on top of everything.
Whether ripping turns at the resort or in the backcountry, wear snow pants and a ski jacket over mid- or heavyweight base layers. When the polar vortex hits, add a fleece top or even a down jacket.
Focus your layer selection on moving moisture off your skin when exploring the back forty or the Nordic center trails. Over a light- or midweight base layer, wear a highly breathable wind layer. Add a lightweight & compressible insulating jacket when you stop to enjoy the views.
When you're in and out of cold and possibly wet conditions, dress with a light base layer and a warm insulating layer, like a wool sweater. When the temperature drops, add a Primaloft® jacket.