Recently I have been trying to go through all my old buildings and give them a far more realistic look. Adding rubble, plaster and stones along with dead grass tufts to give a more derelict effect.
Once sprinkled over the base I sprayed the model with watered down PVA and left to set, repeat a few times and then for any large pieces I paint over with thicker PVA to seal.
I think it gives a far more realistic finish but isn't going to impinge on model placement or stability.
As well as adding rubble I have also been repainting some of the brick work to try to give more variation. So some of the blocks are now brown and cream, but only lightly dry brushed.
Click on the picture below to see how it all began.
And this was how they looed until the make over.