This thread caught my eye for a reason. I was driving to work this morning in my sierra and found myself on a sheet of ice from a spritz of rain, at 65mph (suprised the heck out of me). Felt the truck start to wiggle a bit, slowly let off the power and let the truck decelerate to a safe stable speed. Two hours later a suburban mom (mom in a suburban none the less) spun out and slammed her suburban into a guard rail, in the spot where the ice started and I felt the slip. My guess is she nailed the brakes.
I only kick my truck into 4wd when I ABSOLUTLEY need it, which is rarely, its easier on my transfer case, and I can feel when theres ice on the road alot faster than If I was in 4wd.
Gradual slow movements are the key to any ice driving, anything jerky and your going for a ride.
Deep snow driving can be a total nightmare if its icy underneath, once again, nice slow movements.
If the road is heavily drifted over or the snow is considerably deep, take a hike, (in a safe spot of course). Get out and see how deep it is, it can save you a ton of trouble and alot of money.
Learn how to recover your car from a slide (as stated above) it usually only takes a slow turn on the steering wheel. All you want to do is bring the front wheels to your direction of travel, then slightly,ever so slightly past that point to bring the car back into line. This is something that alot of drivers do not know how to do, I spent my teenage years sliding go carts, dirt bikes, four wheelers, and trucks around on gravel roads, while its not easy on tires (wouldn't recommend it) it definitely helped my overall vehicle control abilities.
Slow down, drifts can whup your backside if your traveling too fast. My brother taught me this lesson, in a rollover. He was young, and over confident in his driving abilities, hit a drift going 50, went sideways, and rolled the truck.