When you are building your tabletop castle you may get carried away with all the alcoves, plasterwork, gargoyles and other medieval gubbinz. Real castles were often way much simpler than that.
The trick is to think backward. Normally you paint shadows in the recesses of a model and then highlights on the edges emphasising how the external light plays on the shape. Fire has a light of its own and so the roles are reversed and the deeper you go, the lighter it will be. »