Here's a mod that adds to the deserts, oasis. In these oasis you can find palm trees allowing you to have palm logs that can be used to make palm planks/slabs/stairs and fences (this type of wood can also be used to make the usual wooden tools).
In these oasis you can also find sand overcome by grass. Grass allows the sand to remain compact so this block does not react to gravity. You can also grow plants on it.
And to make these sand cubes with grass, you just have to take a cube of sand and grass, which will give you two of these new cubes.