Be careful of snow drifts, I've had the mis-fortune of being sucked off the road by one, and my own inexperience in my fathers car when I was first learning, even if you drive slow the wind can push you, that coupled with the whiteout conditions and snow on the road can make it disorienting, to me atleast.
I have since started using my GPS if its really bad out and visibility is crap so I have some sense of where turns are.
I have also had another bout of inexpierence during that same winter about two years ago, came over a crest with a slight right hand turn felt the ass end go completely sideways panicked again and tapped the brakes ended doing a complete 360, and again got lucky and didn't hit anything. Slight and smooth gas to correct a fish tail, not brakes.
As many others have said pay much greater attention than normal, if you're like me and have to traverse back roads you'll find out very quickly how the conditions change from one stretch to the next.
The best piece of advice I can give you, especially if you're out in the country on back roads, or are traveling on road like that. Don't assume just because your road is clear that the rest of the "main" roads are clear, both of my incidents were caused partially due to that thought, I live on a somewhat major road, and the roads I was traveling on were main roads/ state routes. Both of them got about halfway between home and my destination and it turned into a completely different world.
If the weather is bad and you don't have to go anywhere, then don't. That being said go to a big open parking lot near you and practice braking correcting if the car slides and learning how the car behaves, that way if you are out you have a sense of how the car will react on you.