I made some walls to my Turnip28 themed village.
They are made of styrophome that I glued to a thin masonit base and later covered with a mixture of woodglue, plaster and sand and a top of cardboard for the tiles. And later painted them with an airbrush to get that nice transitional colourvariations and then some weathering effects and some flock.
Here with some miniatures for scale.
And here with some buildings and more soldiers in the village. I really like how the aesthetics turned out for this and wants to make even more terrain in this style in the future.