Here is the base making for my latest 1/6 diorama, I block the square to reach the height to make the fox hole for the 30.cal MG team, used foam as filler. The iron brush can easily fix the shape. First apply water base putty on the surface. Second apply the soil from garden, meanwhile spray the white glue+water to settle them. Third apply soda powder as snow, that need to spray white glue+water as well.