I bought several pairs of a "Ducks Unlimited" wool blend sock at Walmart and have been quite happy with them. Most of the hunting I do is in the 30-60 degree range so I haven't needed to use a liner. Whoever said carry a spare pair of socks is right on the money. It's always nice to have that ability when you need it.

Afterbtrying most types of socks, I must say I'm impressed with "Smart Wool" fast drying, non shrinking and comfortable.
I find two thin pair better than one thick pair, for same reasons as others have mentioned. Avoids rubbing/blisters etc.

Careful on being Miserly with your feet. Think of how much time you spend in preparation, you want to be comfortable when you're out there. Filson Merino wool is what I've found to be the best. $20 a pair and they come in different weights for your conditions of temp. BassPro redhead brand is in my opinion the king if you are frugal, $10 a pair w/ a lifetime warranty as someone mentioned. Look at their Turkey boot socks for warm weather. I keep 2 xtra pairs with me. One is a pair of old LLBEAN ragwool. Keep your feet dry and make sure your boots aren't too tight as that will cause cold feet as well.