Mud tires are pretty bad in the sand unless you have the HP to turn them.

All terrains work great in the sand.
You just need to be sure to air your tires down to 15psi front and 10psi rear or somewhere in that area but don't get to crazy with the turns, you might roll a tire off the bead. You don't want to run in the sand with your lockers either, 4wd and 2 open diffs with a gutless motor is the best combination you can run.
Momentum is your friend as well.