Because I'm modelling scenery which isn't spectacular by nature, I feel the need to spend plenty of time working at varying the ground texture on my layout. Here are a few of the things I like to use: Water putty to represent sand/mud... and with crushed shellgrit added... I wrap the shellgrit, available from pet stores, in an old shirt and I clobber it with a hammer. I save it, dust and all, in a container, then when I'm feeling really energetic I pound it finer with the mortar and pestle, ending up with this... I always paint it to match the rest of the scenery after it's glued down, because it's quite yellow.