If you're running radial street tires, airing down isn't going to help much. Won't hurt, but I wouldn't bother dropping below 20 psi.
You don't want a tow strap, you want a recovery strap. Big difference. Recovery straps are much stronger, less likely to snap. Like mentioned above, never use a chain, when they break, they cause damage. Also, you don't want a recovery strap with metal hooks on the ends, again, if it breaks and that hook goes flying, it's gonna cause damage.
Sand can put a lot stress on the drivetrain and cooling system. Think about the difference walking through sand vs. walking on pavement, the same holds true with a vehicle. A spare bottle of water and coolant would be a good idea. For you, too.
A "D" ring or hook mounted to the frame are the best tow points. Axles really aren't great tow spots, but better than rapping around a bumper if those are your choices. I've seen and done it myself on many occasions. No hard yanks, though, ease into it.
Have fun!
