Mid-layer…so, something to wear under a shell? That’s what I like to do. It gives me a lot more versatility. I pack a shell, a cold-weather mid-layer and a not-so-cold-weather layer. If it’s really cold, I can wear them both.

My current favorite is the older version of Patagonia’s Micro Puff Jacket ($180). It’s a trim piece that uses synthetic insulation, so it stays warm when it’s wet. Its slick nylon shell layers beautifully under another piece. And it can be worn on its own. My slightly older version is a pullover with a short zipper, which I like. But the full zip adds a little versatility with very little weight/bulk penalty.

Otherwise, just about any midweight fleece makes a good cold-weather mid-layer. The North Face’s Pumori Jacket ($99) is made from Polartec 200, which is warm and not too bulkly, so it layers well.

For a first layer, I like wool, such as Icebreaker’s Bodyfit 200 Mondo Zip ($70). It’s an excellent midweight base layer with a zip turtleneck. Under a fleece or Micro Puff, it’s super warm and cozy. It works by itself, too, under a shell. I also like Mountain Hardwear’s Microchill Zip T ($55). It’s made from Polartec 100, so compared to the Icebreaker offers about the same warmth and a little better fast-dry ability. I do find wool to have a really wide comfort range, however.

The 2009 Winter Outside Buyer’s Guide is now online. Go ahead, get everything you wish you had gotten over the holidays.