I use the bottles of groundcovers, of miniature soils as well as of various foliage, as a reservoir, which I hold upright in one hand. Then, with the other hand I dip inside with a long-handled teaspoon, sprinkling bit-by-bit as I wish it to be, sometimes heavily, or in more than one pass, and sometimes only once. I often apply a variety of soil and foliage textures and sizes......to the same scene.
I hope this is helpful, Ed.
FrankM