A lighter option is sawdust.
Never thought of that. I´ve got TONS of this stuff.
. Now, I also tend to use natural sand and dirt a lot. For instance, all of my Vietnam minis are based with red dirt that I scrapped up while travelling through southern Oklahoma. It looks exactly like red laterite, and there are even areas that are so red that it looks like what we think “martian red” should be. My property has 6 different colors of dirt, and I used them all extensively. The little twigs and roots that is sometimes found within also adds to great effect! Why buy expensive stuff when you can have free, organic, free range terrain?
That´s a bit problematic and you can laugh about me now but my region got some stuff from Chernobyl back then and I´ve got a spot in the garden a Geiger counter get´s really working. Hm. On the other hand you don´t know what´s already in the house. Got to think about that.
"In strange grammar this one writes" - Master Yoda