Hello there! for this diorama, use POLYFAN plates 20 and 10 mm. The floor is made with a 2 mm plate of foam, it was a bollillo stem, like the walls. Cuts and floor plates made with the cutter or heat, depending on the effect you wanted to. Texturice with fillings, wetting the tip of a thick brush, and taking small golpechitos to the surface, so that it was slightly rough, giving a more realistic look similar to stone. Use colored stone base paint (similar to butter color) and shine white painted using the technique of dry brush. gray door to add water to dilute highlighted.
I hope you'll like it.