Scrap the cotton! Polypro, POLY-fleece, wool, thermax, UA all good. Cotton, sweats, socks, sweaters, ALL BAD except for outer most camo layer.
Thin liner type sock and then wool or other not cotton insulating type sock(s). Make sure you feet have ample room. There is a point that more socks, even the right kind will make your feet cold as they restrict blood flow. I am also amazed how much warmer the rest of me is when my head is warm. A good wool or fleece hat and a fleece neck gator work miracles. In addition it is very important to not get overheated walking in and or climbing up into the stand. I under dress on the way in and layer up in the stand. I have a couple buddies that swear by those over boot things when it is really cold.
Hope this helps
reo