Aswith all other aspects of cold weather clothing, layering is the key. I ski between 40 and 60 days a year in all conditions from -30 with wind to 60 and slushy and I use only one pair of socks, the smartwool lightweight socks. Because its an active sport the blood is always pumping and the feet very rarely get cold. While on stand I use the same pair of socks, the wicking feature is the key. When it goes below 45 or so, I'll throw another pair of socks of varying thickness(depends on temps) over the smartwools. Sweat is the enemy, and dont wear a sock a second time due to the fact that the dried salt from your sweat will attract moisture, and moisture(sweat) will make your feet cold.