i'd like to add a bit to this sir! Since it happens to me a lot, ive become quite an expert in getting unstuck!
Step 1: Deflate. Even with sand tires, u need flotation to get through, and u can only get flotation when u have deflated. 10 psi is not unheard of (On Cooper STTs 5 psi works pretty well). I'm assuming u have access to an air pump (which is again, an important piece of recovery gear - dont go off-roading if ur recovery gear isnt complete).
Step 2: Engage lowest possible gears and all available diff-locks.
Step 3: Start driving SLOWLY. do NOT accelerate or try to power out of a stuck in the sand. start driving as SLOWLY as possible.
Step 4: Start turning steeing wheel left-right-left (sawing).
Generally, this will get you out of a sand stuck on a level surface (sand dunes is entirely another story).
But if this fails, then:
Step 5: Get that shovel which Janj was talking about! The idea is, to try to dig a path for the wheels to follow. The gradient should be gentle.
Step 6: Shovel out any sand upon which the frame / chassis might be resting.
If u STILL cant get unstuck, then try the jacking up / tire mats technique as explained earlier.
Ofcourse, instead of going thru all the trouble, u can have someone snatch you out, but again, that is another story!