I posted the first version of this map in the "new member introduction" forum a few days ago. It's a map I created mostly to practice some of the techniques I saw in the tutorials here and to familiarize myself with GIMP. Here's the original again:

Click image for larger version.  Name: island.png  Views: 619  Size: 935.9 KB  ID: 30378

In response to some constructive criticism, I:
1. Created a layer mask with feathered edges to smooth out the coastlines, and applied it to the base land layer.
2. Used a Gaussian blur on the "grass" layer and the "forest" layer to reduce pixilation.
3. Toned down the color intensity of the "forest" layer a bit.
4. Used a Gaussian blur on the "river" layer to make the rivers and lakes smoother.

Here's the revised map:

Click image for larger version.  Name: island-2.png  Views: 499  Size: 774.0 KB  ID: 30379

The pixel dimensions of the image are relatively small ( 1024x768 ) because a) I started it on a laptop using the laptop screen (not much screen real estate), and b) because this is a "practice" map, I wanted to keep the size small enough that I could work quickly.

Thanks in advance for any constructive comments and suggestions.