If you want to keep your feet warm, keep your face warm first.

If your face gets cold your body starts limiting blood flow to the extremities. What's the furthest extremity from your heart?

If your feet still get cold, put carpet on your tree stand.

Now you need to start looking at your boots if they are still getting cold. Extra wool socks are good UNLESS THEY MAKE YOUR BOOTS FEEL TIGHTER. Better a loose fit your toes can wiggle around in than a tight fit with two pair of socks.

Next thing short of new boots, put bread sacks on your feet before you ever put socks on. It keeps your insulation dry and fluffy. Wet feet get cold.

When it really get's cold I get out my Iceman Pack boots I bought for ice fishing in WI. Otherwise I wear my LaCross pack boots with removable insulation for different temps.