Admittedly, tiles depicting different kinds of sand are going to be difficult to create: it is a desert, all you can see is sand and more sand. This set tries to change things up with rock formations and a few trees, but there is only so much one can do, so the back of the tiles have...water, which is even more featureless. Supposedly these water tiles can be used to depict silt pools, but no one is really buying that clean, crisp blue tile as silt, especially since it has waves drawn on it! Also, the sample picture is using those water tiles as--you guessed it--water. A gigantic ocean, no less, with a boat and a pier. The boat and pier are 3D pieces from 2 of the 6 boards in the set. Other 3D pieces are buildings and, bizarrely, a double-decker bus-like vehicle. To me, the 3D pieces are a total waste because they do not scale properly with the flat tiles and look ridiculous when next to a tree that is 2D because it is just a painted image. The Harrowing Halls set has this same problem.
So, what you end up with is a handful of tiles depicting vast stretches of ocean on one side, rocky plateaus in sand dunes on the other, and a few 3D elements. Your ability to make a decent map with these tiles is severely limited: the shading on the rocks makes it awkward to put together nice-looking terrain, and the small number of tiles (due to the 3D pieces) require you to buy more than one set if you want to make a map of any substantial size (like to get something out of range of those ICBM-shooting rangers who can target from 20 squares away).
WOTC has seriously shortchanged the consumer with this set, which is sad because sandy terrain is a much needed and welcome addition to the map tile collection. I'd really like to see them stop making the useless 3D pieces, but I know they won't--it is a marketing ploy to force you to buy more than one of the same set just to get a good number of tiles.