One of the best things about making a diorama is the fact that you can improvise a lot of materias by using common found around the house stuff in the diorama. And make it look terrific. A good example of this is shown in this tutorial on how to use a real brick to get some terrific brick effects in your diorama. This tutorial was submitted by a web visitor (Glen) and my thanks go to him for submitting all this terrific stuff.
You can see that the diorama is a WWII scene of a half destroyed European Cafe. And this means lots of red bricks! so let's see how to use real bricks to get this effect.
A note: I also have a tutorial on how the Cafe was made from a kit and improved upon with some nice additions like a wooden floor and realistic period piece posters on the walls: Upgrading the European Cafe
And you can see more pictures of this completed diorama right here
Here is the completed diorama. Notice the use of the red bricks.

Ok, It is just a matter of getting yourself a brick. But the picture shows that all bricks are not made alike. In particular you can see that these two bricks have markedly different colors and textures. Just something to think about. You may be looking for a certain shade of red, or you can use various shades to vary the terrain.
Okay, Break out the hammer and have some fun on the brick. But be safe! Wear safety glasses and I recommend you put a cloth right over the brick and hammer it through the cloth. This will minimize brick fragments flying around.
This is terrific. We have lots of brick material we can use on the diorama. And notice how it comes in a lot of different sizes, some of it is like dust and lots of it is in chunks. This variety is important. You can use these pieces in different places and in different ways.
Now you can spread the brick rubble on the diorama.

You can use any type of white glue. Just brush it onto the diorama then you can sprinkle on the brick dust and brick parts. . (Glen is using PVA glue here) And PVA glue is a type of white glue similar to Elmers glue or carpenters glue. Larger pieces can be glued on individually.
Here we have sprinkled on the brick dust and brick parts directly to the section we just applied glue to.
There we go. The brick is laid down and we are ready to add the building and other terrain features.

I have another tutorial on making rubble in your diorama
Add realistic rubble to your dioramas:
This technique uses cork and is easy, inexpensive and looks great, particularly for battle or combat scenes. Perfect for military dioramas. I have an included video tutorial Rubble in Dioramas using Cork