I use 6x6 posts I had laying around. I cut them down to 24 inch and 12 inches long. I put the 24 inch ones down first, side by side, then two 12 inch ones on top of that side by side then one 12 inch on top of that. I have a farm jack that I put under the coupler to hold up the front as I raise the tounge jack so I can put the layer of 6x6s under it. I put the bottom layer parallel to the frame then layer two perpendicular to that and then the top layer parallel to the frame again. I also make sure I chock all four tires before unhitching from the truck.