I usually put 200 to 300 lbs of sandbags just rearward of the axle. Gives pretty good traction and can throw under the tires when stuck. This year, since my tonneau bit the dust, I am free to do an old trick, which is to shovel snow in the back. Did that one time and I would drive down unplowed sidestreets after a 10-inch snowstorm, with no traction problems at all. Yeah, I had the bed filled to the brim and the rear hanging low. Ha ha, but the traction was phenomenal.