I use sock liners underneath my heavy wool socks. Essentially, they are really thin nylon socks, thicker than women' s pantyhose [].

The way these work: The tight nylon sock will wick away the sweat, into the wool blend sock, away from your feet. This creates a small barrier between your foot and a sweaty sock and is much better than just sticking your feet in the wool sock.

Since I' ve been using this method, I find that my feet stay warmer twice as long.

My boots come with Thinsulate liners in them also. I have however used the felt lined boots and find that they work well too.

The absoulte key to keep your feet warm..... Keep them dry and sweat free. If its a cold morning, take a bit extra time to get to your stand. You sweat, you get cold. It' s as simple as that.