I gathered up some sand from the side of the raod. Here in the Northest USA a fair bit of sand is laid down on the roads every winter. The result has small pebbles and variable sized grit.
I use a mix of white glue and water and sand to fill the areas between the stands. I do this to provide a level ground for the figures -- so they aren't standing on small hills. If I do nothing else, the overall texture is fairly smooth, broken only by the occasional pebble.
If I want more texture, I take some dry sand and sprinkle it over the base. When this dries, I have much more texture.
Either way, I let the white glue dry over night. Then drybrushing. I then add flock, either over the whole base or just in spots, depending on the look I want.
Does this help?