[cypher]

Egg boxes & coconuts are two of the favourite things with mine, small terracotta flower pots are good too, simple & free things usually seem to work best!
Do you have a sand bath? They do like a good size, fairly deep sand bath but you can use anything, ceramic bowls, plastic boxes, whatever you have to hand or can get easily that will fit in the cage.
If you can find a nice wooden house without a base that would probably be preferable rather than a plastic house.