Currently building a small stone bridge to cross the river below the cottage. The basic structure was constructed from mount board then Das clay was applied, once this was dry, the stonework was scribed. I have used the stone coloured variety of the clay and when it is fully dry, it gives a really authentic base colour which would probably only need weathering to complete the effect, although I am going to follow the example of Alan @Tullygrainey and paint the stonework in various colours of beige and brown.
The extra slab of clay in the final photo will be used to create the coping stones and these will be applied individually.