Gear Guy

Manage your moisture. The inside of your tent will be full of crystals from your nights rest. If you are camping for multiple days. Dry out your gear. Wet gear will keep you cold.

I always like to have a nip of good whiskey followed up by a good piece of chocolate just before bed. Gets some sugar in your system and opens up the blood vessels which helps warm the bag. Also carrying a lighter bag and use an insulated pant in camp along with a good down sweater. Insulation is insulation and if you are wondering around a cold camp nothing beats insulated pants.

As above (condensation), and also keep your boots in the bottom of the sleeping bag. Nothing worse then frozen boots in the morning. And bring heat packs for hands and feet!

Jon (above) said it. In short, moisture management is the most important thing. You don't want to put anything in your sleeping bag that may have absorbed any of your perspiration. That includes boots and the long johns that the gear guy recommended (if you're overly warm at the beginning of the night, close fitting long johns will get wet and because they move with you, they won't dry and you'll be freezing in the morning ). Instead, use a bag liner. Not only will it keep you dry and warm, it will also keep your sleeping bag in the same condition and it packs way smaller then long johns.

An old NOLS strategy involves "sacred socks." Bring along a pair of heavy wool or fleece socks and leave them in your bag, even when its packed. Never wear them outside the tent. Put them on at night, take them off in the morning. You simply can't beat the comfort of warm socks. Oh, and you can always lay your puffy beneath you in your bag if you don't like to wear it while sleeping.

An old NOLS strategy involves "sacred socks." Bring along a pair of heavy wool or fleece socks and leave them in your bag, even when its packed. Never wear them outside the tent. Put them on at night, take them off in the morning. You simply can't beat the comfort of warm socks. Oh, and you can always lay your puffy beneath you in your bag if you don't like to wear it while sleeping.

Take it easy on the hike out so as not to sweat i.e stay dry.

Don't forget to empty your bladder (and everything else) before you go to sleep. It's tempting to hold it until morning when it's freezing outside, but your body has to work overtime to keep waste warm, and when it's eliminated, there's a big noticeable difference in how much warmer you'll feel.

Some isolation under you http://golopper.com/magazine/22/03/2011/52/about-mattresses

and dont forget to drink ovaltine ;-)

Hot water in a bottle at the foot of your sleeping bag is always nice, just make sure the lid is on tight. I've seen a good friend of mine wake up with part of his bag frozen to his pad. Down booties thought they seem a bit over kill and weak are great. Frozen boots do suck but we've had really good luck with cross country ski boots when skiing or snowshoeing, they just don't seem to absorb water and freeze. I’ve got an overbag with an integrated die cut foam pad that I won’t leave at home, great as an extra bag/pad and very versatile outside the tent.