I'm also experimenting with mountains. Alas, so far my results are not the best, but perhaps your minitutorial has given me some hints (thus, receive some rep!)

But I think I also can give you an advice, I think it's better to work on different levels.
I make one for the outline, one for plain color, one for texture/noise (on multiply, above the color), then one for shadow (hue/saturation regolation level set on multiply, with low brightness and perhaps a hint of dark blue hue to have the night dark effect), and one for highlights (again, hue saturation level set on hard light, with high brightness and a hint of yellowish/gold color for sun effect).
Working on different levels allows you to change colors and brightness afterwards, and it's cool to see various effects.

Alas, my main problem for now is to draw convincing mountain shapes. They always have a little "something" that I don't like.
However, I'm trying with your method now, and I hope my hints can help you.