You will find this varies from person to person. I have tried basic Army issue to the thickest sock I could wear and stuff in my boots. The main thing is to try an keep your toes moving to keep some heat in the socks.
If you can find Canadian Mukluks, you'll be just fine down to about -40 degrees.
Alternatively, a combination of white 100% cotton socks inside G.I. issue wool socks are hard to beat, when worn in quality breathable footwear.
I'd avoid the surplus G.I. "Mickey Mouse" boots; they will cause your feet to sweat and there is no way to vent the moisture. After a few hours, the skin on your feet will wrinkle and the stench will make all around wretch when you pull those boots off.
Thurlo rag wool socks are great but if your feet sweat and stay wet they will get cold. If you sit in a
Stand for hours any boot and sock combo that won't make your feet sweat walking to the stand wont have enough insulation to keep them warm when sitting. Over booties or swapping hunting boots for insulated booties might be the answer.
Also check your chair to be sure it not cutting off circulation to your legs.
Thank you for the replies so far, keep them coming.
I've got boots covered, and it's a good wool sock that I'm looking for. Durability and a high wool content are the top features I'm looking for. It's so damn hard to find good wool socks these days, recommendations from people who buy them and use them are invaluable.
Smartwool and Thorlo are both great. Get the thickness you need for your planned activity. The smartwool will be a bit warmer but I think Thorlo are more comfortable. In my experience, smartwool knock offs are not worth the savings.
Smartwool all the way. I've been in Vail for a few days and I'm stuck here until my pilot feels safe to fly. Smartwool has kept me nice and cozy on the mountain.
carthart wool/cotton blend socks are great. thick, but not to thick and since its a blend they breath well and dont stink up your feet at the end of the day
Moved here from Illinois. Still walking around out here in the country in my sandals lol. Up north I like the old heavy Army green socks. It's more important that you have good boots. So thankfull I no longer have to spend 6 hours a day out snowblowing and digging out.
+1 for Smartwool. Been wearing them for years. I wear the medium hikers and run in the their running socks. When you buy them the price stings a little but they last 3 times as long as most socks so it's only fair they cost 3 times as much.
I had some thinsulate socks when I lived in CO that worked well. In TX... I don't really find them necessary. Visit someplace thats actually cold and I bet you'll find some good socks on store shelves.