Tonight found this great GIMP tutorial for how to create a glossy button from scratch working with millions of layers. I'm must too lazy for this kind of detail, but it is a great tutorial for how to work with layers. And how to merge all of the layers and export the image as .png. Previously I just asked GIMP to ignore everything when I saved, but now learned that the export option has a good reason for being there. 
[video=youtube]
[video=youtube]