Since both of my jeeps spend more time on the sand, I keep them at about 18 -20 psi
Do not run in the sand on fully inflated tires, it just beats the hell out of your suspension & drivetrain. In addition it creates washboard ruts for everyone that travels behind you.
My place is in Corolla at the north end of the Outer Banks, Rt 12 ends about a mile from my house and from there it is ten miles of beach and trails all the way north to the Va line.
Just a few tips:
Watch your speed on the beach 15mph near people and 30mph otherwise
Drive up near dunes or down at waters edge
Park in the middle of the beach
There are sand trails (mapped streets) behind the dune lines, a GPS helps
Stay off dunes
Watch out for wild horses, deer, fox and wild boar
bring a camera
Have a chitload of fun