I use a very simple method to use on my bases (altdorf themed army btw)
First the bases are (just as my figures) spray coated with Chaos Black.
Then completly done with Bestial Brown
PVA glue on the top and add sand (I have a pot of rough play sand)
Then another coat of Bestial Brown
Codex grey on the larger grains to resemble little rocks, highlighted with Fortress Grey
Smaller but still out standing grains I then highlight with Snakebite Leather
PVA glue on a few spots and then add some static grass
and done
Hmm it goes alot faster then it feels summed up.. (besides waiting on the PVA glue to dry)