sand bases, if there's room add some small rocks.
spray undercoat black, basecoat of scorched brown, single light drybrush of bleached bone.
paint rocks dark grey with a fortress grey highlight.
add plastic terrarium/fishtank plants that you can buy very cheaply at petstores.
finished.
plastic terrarium plants have the proper scale for use with lizardmen.
i'll post some pics when i can of the swarm bases i'm working on, i use diferent plant types mixed together.
this give a real jungle feel to the bases.