I create a layer called shorelines and quickly using a soft brush outline where I see them (shorelines vs. mountains) within the tile itself. In a strange way I feel a bit like Leonardo when he gazed at the rough marble chunk that he turned into David. Now if only I can not completely botch the job, LOL.
I then duplicate the base layer, de-saturate it, create 2 layers for the Sea, and one for the Forests - haha, I have no idea where this is going but I don't want to think, I just want to get something down to see if this is at all plausible. I use some galaxy brush and paint a couple different colors on top of one another where I want forest. (I mosaic'd the forest into tiny triangles and then painted over the top of that again, went back burned the middle areas of the larger forests, then dodged around the edges to give more texture to it).
Hehe, my wife says that blue has got to go but I told her not to worry about that, I'll tear into it soon enough.