You’ve heard it since you were a kid: wear layers. Dressing in layers is even more important in warmer weather. In any temperature there are some better ways to layer than others.
Base layer: Picking the best base layer is important. This layer can mean the difference between sweating — and subsequently freezing — all day, or being comfortable. Choosing a layer with a somewhat snug fit that wicks away sweat, like nylon or polypropylene is your best bet. Thermax can keep you a little warmer if you tend to get cold. Remember, if you get extra warm during the day and shed your outer layers, this layer will need to keep you warm enough and modest enough to be seen in.
Mid-layer: A mid-layer is often looser and can help pull moisture away from the base layer, so polyester, wool, down, or fleece work well. Having a collar on this layer can come in handy if you end up taking off your ski jacket on warm days.
Outer layer: Your outer layer helps block the cold, wind, and water. Make sure when you try on ski jackets that you zip and fasten them all the way up in the store. You need to be able to move well without enough room for snow to get in the bottom if you fall, and the collar needs to be comfortable around your neck and face. The best outer layers for snowy days are insulated and are made of Gor-Tex, eVent, Pertex, Windstopper, Dryride, or HyVent fabrics.