Mountain Ice-scape painting with a small climber having a rest
A tip i learned while painting was that when painting snow, it becomes slightly reflective of its surroundings. A blue sky would give a bluish tint in the shadow etc. Don't just use black or grey when adding shadows.
A technique I learned is by using images of rocks, mountain, ice etc and using the lasso tool to mask out areas of the painting then using the stamp tool to clone from the photos to the selected area from the marque selection.