This one for you Nef. Still bezerking the Beeber.
Here's how I do my bases, it very cheap and easy. I use 4 paints for this tutorial after priming. Codex grey, scorched brown, balor brown, agrax earthshade and dead white.
So after primeing and base coating the model.
I put a base coat of scorched brown on all the sandy/small grit areas.
Then I base all the rocks with codex grey.
Then give everything a heavy wash of agrax earth shade, make sure you get into all the nucks and crannies.
Then give everything a good dry brush of Baylor brown.
Then give the large stones and some selective areas a dry brush of codex grey.
Then add some white to the grey and dry brush any edge areas on the big rocks.
Then add some static grass in some small areas. I add a blob of super glue in a suitable looking spot and just sprinkle some grass on, turn it upside down and tap off any excess.
Hope this helps.
Next time I'm doing some basing I'll do a tutorial on how I actually make them up.