Smooth coasts & Style?

[Sular]

Alex, I hope the attached pair of images will be useful. All images were made in Photoshop 7 (I've used CS5 as well but I don't personally own a copy, but the general results should be similar.)

The image itself is 1400x1400 pixels. The outline was drawn with a 3px round brush using just a mouse on a separate layer. I then selected the the the area outside the outline (the "water" if you will) with the magic wand tool. I then inverted the selection, smoothed the selection under Select > Modify > Smooth by two px. On a new layer I painted the landmass green with a large brush.

As you can see, some of the coastline details from the outline are lost in the process. If you spend a lot of time selecting tiny areas carefully, and/or selecting inside the outlines to see if that returns a better result, you can generally get a fairly close approximation of the what your outline originally looked like.

I hope this is useful.