I am making a diorama in a chest that I found so I figured I'll do (redo) a tutorial to go along side it- in hope that it might be useful to someone.
Saw a decorative chest at the weekend market. It gave me an idea of making a diorama of Beastmen ambushing a caravan inside the chest.
I will be using Beastmen miniatures from the games workshop along with Scared people from Terrorized Miniatures.
I got half way through making it and thought it might be useful to someone (hopefully) if I upload/reupload a tutorial I did a while back on realistic rocks and rocky terrain.
Materials
Grout PVA glue
No-nails Glue Super glue
Old clippers Baking soda and sand
There will be more little bits and bobs, but these are the main things that you will be needing.
Textures
-Baking soda is very fine so it’s closer to dirt and sand in the scale we are dealing with.
-Fine sand is used to brake up the texture giving it more variation and depth. I usually steal this from ashtrays that has fine sand (can't buy class)- but you can buy this at any pet shop that has aquarium stuff (aquarium sand).
-Just sand from a beach or construction site. This is used for forests or rocky terrains where there are a lot of pebble and stones.
Grout
I do a huge batch of this because it's always useful to have around for random projects.
The make!
-Kitchen foil
-A container
-Grout
It comes in many colors- any will do. I normally use black, brown, or grey because if I accidentally chipped any paint off- It's hardly notice able. Just slowly mix with water until you get the consistency you see in the picture.
Pace foil down for some texture
Mix and place grout in
Spread it around a bit so it’s not too thick
Take it out when it's dry.
Hammer time!
And you get rocks 
Cut and sand
Sand to get flat surface or use clippers to cut to the right size, shape, or brake/trim off bits.
No matter how you clip or brake it- it will always have a rocky texture.
Don't throw the cut off bits away! It can still be used for many things.
Stone slabs
-Flat surface -Sea salt
-Clippers -Grout
Sprinkle some salt on to the flat surface that you are using.
Mix some grout and slop a blobs onto the salted surface.
Leave it to cure completely before taking it off the surface.
Trim off the rounded edges and get it to the shape you want for all the slabs.
Arrange and glue the pieces where you want it. Sand, baking soda, and small rocks can be put on for more effect and texture.
when pouring the grout pads- make varying thickness so you have more to choose from for what ever project you are doing.
Let's get back to Chest diorama.
I use plastic cups and random pieces of wood to raise the level of the chest's floor
I then start gluing the bigger grout pad onto the diorama first just to get a rough shape of the landscape. I do this randomly adding and taking away as I see fit. once I'm happy with it- I blend/ hide big gaps with smaller grout bits.
Baking soda is then glued onto the areas I want to have dirt.
At this stage- it will look a mess.... but grit your teeth and push through-it should be fine...
but if it's hard to the over all shapes and details any more- give it a light dark wash all over. Thing can still be added and taken away at any point.
Once you are more or less happy with it- primer it up and move to painting.
To be continued...
Extra, extra, extra!!!!
Forest floor
-Apply no nail glue to base
-stick some broken Grout pads on
-stick some twigs and roots on
-add baking soda for dirt
- paint it the color you want
For foliage and fallen leaves on the forest floor- gluing green tea leaves from a tea bag in random areas works really well.
Cracked earth
-stick some duct tape on the flat side of a grout pad.
- STOP! Hammer time!
- put no nails on the base
- press the taped grout pad into the glue
- carefully remove the tape
- slowly push out and separate the sections
- baking soda for dirt and paint
For smaller bases use thinner grout pads and remember that grout can be cut and sanded down to shape very easily.