The sand up the beach from the water line can get extremely soft and powdery in spots. It's all about keeping momentum. Once you're moving, don't stop unless you have a reason to. There have been times in my 4WD Ranger where it was foot to the floor, all 4 tires spinning, and going a snail's pace forward, and eventually sinking in, because all you're doing is displacing sand.
I've seen guys with diesel F-350's lifted to the moon and locked on both ends on 44's bury themselves to the axles right on the beach, and I've seen guys in bone stock Ram 1500s blast through the same spots pulling a 30' trailer.
It's all about keeping your foot in it and maintaining momentum. You can look in the sand where other people's lines were.
Also, be careful driving in un-touched sand. In the sun, going at speed, what looks like a 6" ledge could be a several-foot dropoff or giant hole, and back in the dunes, it could be a 60 foot drop.