The most important part of dressing for skiing is warmth. Your base layer should be moisture-wicking wool or synthetic to keep you dry.
Even if it's not snowing, you'll want waterproof, or at least water-resistant, outer pants and coat. Chairlifts can be wet or dripping. In wet snow, one fall could soak through.
Wear another removable layer, a fleece or sweater on your chest to ensure warmth. Make sure your bra doesn't ride up, as it will be difficult to reach under several layers.
Wear a face mask. Sun at mountain altitudes is strong and can permanently damage the skin. Wind and snow can cause redness and frostbite.
Make sure your base layer pants and socks don't wrinkle in your boots. Even the smallest slouch can cause pain on toes or calves.
Make sure at least one of your upper layers is tucked into your pants so snow does not touch your skin if you fall.