Welcome! Feel free to post some in-progress threads well before you get to the end of it because showing the things that didn't work well is often as...
I agree with Turambar's recommendations. I will also suggest that the better the quality of the input, the better than quality of the results because...
Saving for CS4!, Corel Painter X, Fractal Terrains, Wilbur, Anything and Everything Else!
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Dollhouse Syndrome = The temptation to turn a map into a picture, obscuring the goal of the image with the appeal of cute, or simply available, parts. Maps have clarity through simplification.