I made a planet map by playing around with the fill pattern tools and some blur, then shrank it to create the corner symbol on a map.
I had created a small palette using the blending function of the eyedropper tool in GIMP and was able to expand it into a wide range of vibrant colors using layer techniques like overlay and multiply - and direct use of the hue slider 
. I have some basic idea about how to apply shadows and highlights through the same methods, but I definitely need work.
I made a basic dagger, a spiked shield and then reused the outline of the spiked shield to make a jeweled ring. I experimented with black outlines for more pop. Here are my variations:
