Change the ground to dirt ground, atleast at most places. Think of where to put details, preferably near the cave walls.
Stop using autoborder and doodads <-- I say this in 90% of my posts xD
its cool, its like an underground castle? so you might put grounds like black marvel covered by the dirt..burried coffins, coal basins, torches, trash.. more big rocks and it will look much better
kokoko~ why is autoborder bad? I don't understandAnd why is doodad bad? Better than searching for each thing in RAW
takes so much time but result is same anyway