I made the first shot below while the sun was between clouds. I had hiked all over the dunes looking for a composition like this with a leading line, ripples in the sand, and no footprints. The low side light produced some nice dramatic shadows in the sand, which was also one of the elements I was looking for.
Sometimes we shoot like we are in a hurry. Set up, make the shot, move on to the next one. It pays to slow down and wait for different lighting. You don't know what you will get.