Preparation
Base edges: I always paint the edges of my bases before applying any groundwork as it gives a far neater finish. I usually use the first colour given in the recipe, although for my North American, temperate scheme I quite like black edges.
Groundwork:This comprises two layers of sand and PVA (white or wood glue). The first layer is fine sand; mainly to texture around and across the figure bases. The second is a layer of coarse sand to hide the figure bases. This basic groundwork doesn't need to be painted, just highlighted (see Temperate #2).