Here’s a quick way to make a lot of light weight rock pile scatter terrain and use up some offcuts in the process.
Break up a cork floor tile into random shapes (try to avoid any straight edges) and glue them to a base with PVA.
Mix up some PVA, Sand and Ready Mixed polyfilla along with some dark grey paint. Stipple the sludge over the rocks and in patches around the base.
Drybrush the rocks up to a mid grey and hit the very edges with a very light grey – tint patches of the rock with earthy browns. Paint the ground with a dark, earthy brown, followed by a light brown drybrush.
Flock the base (I used static grass sprinkled over patches of pva – blowing on them as it starts to dry helps them stand up a little).
Stick on a few static grass clumps to vary the vegetation a bit and tint with brown and dark green washes and you’re done.