Creating a desert diorama featuring an old gas station/garage

Hello, I am putting together a diorama as a display for our blues/rock band's tip jar and business cardholder. The garage is built and the next step is to add some barrels maybe some car parts around the building. My vision is to have the garage surrounded by cracked desert playa with sagebrush and tumbleweed.  Has anyone experimented with clay or other material to achieve such an effect?  Any suggestions would be greatly appreciated. I also want to add some lights both on the outside and inside. I would appreciate any suggestions as to products you would recommend (ie power supply and led lighting). Thanks so much. Angus