Shoot at half-light
The eerie half-light before sunrise or after sunset is perfect for giving your mountain images a different look.
These conditions are similar to shooting at sunrise and sunset, but because there isn’t any direct light on the landscape, the mountains and rocks can look even more foreboding.
You can use a graduated Neutral Density filter to balance the exposure between the sky and the landscape, but it’s best to use an exposure that keeps some of the rocks in shadow to make your shot more dramatic.
Remember that mountains can be dangerous places, especially in the dark. At the very least take a torch, plenty of warm clothing and some basic provisions.