Hopefully someone can get something out of my workflow.
Up till this post everything has come from a follow along with the tutorials listed in my first post.
In an attempt to detail the mountains a bit I have:
1. Merged all the border layers to the Margin layer.
2. Selected the Snowcaps layer.
3. 'Select by Color' the brightest snowcap (Threshold 100, Select by: Value).
4. Added a dropshadow (Color: Black, Contour: Linear, Noise: 0, Blending Mode: Normal, Spread:0, Size:5, Offset Angle: 120, Offset Distance: 5).
First thumb is a screen of my workflow. Second is the latest image.