I agree, and great advice.
If you drive a Auto, and the sand is a bit soft, (not just hard beach surface) try and keep overdive off, don't be afraid to make it easy on your car and go into Low, its best to go into Low range and have the gearbox cruise along in third gear, rather than stay in H4 and have the gearbox in second gear (or change between 2 & 3rd all the time)
2 Maxtrax is fine, ive done lots of sand driving and never got into trouble, but while waiting for the tide/s over on straddie one day, i got myself stuck on purpose (Big sand hill, tyres @ 45PSI , car fully loaded with gear) to test my out Maxtrax , they worked quite well (i only have 2)
I found under rear tyres worked best on the hill, but its easy to try both, BTW, i went back to the same hill with tyres set low, and could drive up it easy.