The one covering the Calais area gives a pretty good idea of the terrain fought over by 10th Panzer Division and 3RTR on 23rd May 1940, which happens to be the subject of my game for Joy of Six next year.
Using a suitably sized paper mask to mark out the table area I came up with this.
I started off with a suitably sized offcut of PVC board. I chamfered the edges and then painted on the field shapes in Modpodge before scattering on sand. When this was dried I sealed the sand in place with another layer of Modpodge.
When this had dried I painted the ditches black (and varnished them) and did
the fields in a couple of shades of brown.
The fields then got another coat of Modpodge onto which I scattered fine flock, a couple of shades of green on most of the fields but a coarser yellow material on one of them. The whole was then sealed in place by dripping on watered down Modpodge and allowing capillary action to carry it through the flock.
Finally the fields received a fifth and final coat of Modpodge (slightly watered down this time) onto which static grass was added using an applicator. I worked one field at a time so the glue was still wet when the static grass was applied.
The two brighter green fields are the same static grass on different shades of underlying flock. There's actually a very subtle difference in colour at the end of the process but it's not obvious in the photo.
I have some stand-alone ditches made from strips of Poundland floor tile but I think this integrated module gives a better look.