Sir, our little group has two methods of creating wargaming terrain. There are photos of both on this forum.
One way is the method used in this ACW game. Polystyrene tiles are shaped using a sharp tool or an electric cutter into hills, ravines, rivers. Then a cloth made from green dyed teddy bear fur is drapped over it. To enhance the rivers, painted & textured latex is crafted to fit into the grooves. Clearly, you can move the tiles to create nearly any landscape.
Our other method is to lay a wargame mat over a flat surface & put the hills etc on top.
eg:
Now, no-one would say the second method is superior to the first. But we mostly use the second because of the time factor.
For a night time or afternoon game of 4-5 hours, maximum, it takes up too much time to set up the polystyrene tiles, Additionally, to transport it, fills a van.
The second method is quick to set up , transport & store. We only tend to use the tiles for "special" games where we have lots of time.
Please ask me anything eg where to get game mats etc.
donald