I usually look stuff up before I try it, in this case I just jumped in and experimented with putting rocks and glue on the base. I made the rocks and sand by crushing pieces of volcanic grill coals (sold for propane grills and fire pits). The flocking is Gale Force Nine products.
Here’s my first ever detailed base with sand, grasses and rocks. As I mentioned, I crushed up a couple of different barbecue grill “coals” (the kind made from lava rocks) and used the pebbles and sand, along with a couple of Gale Force Nine flocking/grasses. Oh, and Aleene’s Tacky Glue. I will be looking up tutorials on how to glue better and make sure things stay. I know the rocks will be falling off this base for eternity if I don’t figure something out.