Creating specular map for mesh bodies

[Lentissimo]

Does anyone have any tips on creating a specular map for mesh bodies like Maitreya, to produce a dynamic oily/glossy effect? I've seen it on a few people, and skin creators like Egozy provide it in their appliers, and looks pretty cool. Is there a template? I have the Maitreya dev kit with the UV maps, as well as a few skin kits. Though I don't think I need an actual skin for it? It's just gloss that goes over any skin.