Here in Florida you have two surfaces you can off-road in, sand and mud. We wheel in some REALLY deep sand and you become VERY good at driving in it after a while. We don't use "sand ladders" here or anything like that.
There are two tricks to driving in sand that you learn early on. First is to use high 4WD as much as possible. Auto transmissions should manually shift, getting the speed up slowly until sufficient rpm is achieved to upshift to the next gear. When the sand begins to thicken, a quick downshift will bring the rpms back up and get the truck out of bog mode.
Second is to substantially lower air pressure in the tires (15 to 18 psi). If climbing a hill and you are not interested in backing back down, make sure your speed is up high enough and don't let up on the gas until over the top.
One important thing to remember, if you bury the rear wheels by showing off in 2WD, most likely you will not drive out, even with a locker. Once you have drag on the frame or diff, your party is over. Also, the newer your tires, the more likely you will get stuck. New tires tend to dig their own grave if you give it too much gas. You want to stay on top of the sand, not sink into it. Mud tires do not usually perform well in sand due to the cleats. Those cleats are made to move mud and act as paddles. In sand, they only dig you down deeper.
One final note and this is one that Xterras are not known for; horsepower is king in the sand. You can still make an X perform well in sand, but don't expect to be doing sand drags. I went head-to-head with a Hummer, but at 45 mph I ran out of steam (or flotation) and he toasted me. Those wide 38's laid me to waste.
Don't know if that is what you need them for, but just a few hints from us poor boobs who have nothing else to wheel in.