Dedicated snow tires make a world of a difference. If you have normal "all-season" tires, I'd highly recommend getting a separate set of wheels with snow tires on them to change out during the winter months. You'll be shocked at the traction difference in snow. Weight in the bed also will help tremendously (like 500+ lb).

As an aside, make sure you're using 4 wheel drive correctly. 4H should never be used on pavement unless it is snow covered/slick. You will damage your vehicle using 4H on high traction surfaces. 4A can be used in any conditions, if your truck is equipped with it.