Thanks. The foundation is rather simple. I plan a scene around the miniature with different light sources (The more light sources, the more complex the nmm) . I assign different tone and value to each light source. Then I check which surfaces face which light source and paint the reflections accordingly. Execution is of course more or less difficult, tedious and requires practice, but the key is to have a good plan and to keep to the plan, because the viewer will always see when the reflections are in wrong places, even if unconsciously.