Best way to draw mountains

[Startraphell]

I have explanations for both a realistic, and a stylized type of mountain.

If you wish to make realistic work, you can do with either topography or ridgeline. With topography, it's self evident. You draw circles going up with the height values of each mountain. With the ridgeline effect, you do something similar. You draw a series of ridgelines going along the length of the mountain ridge, with offshoots where appropriate. Then, you gently pencil a few topography layers, then shade each one as appropriate.

With a more stylized look, you draw triangles. There's a load of approaches you might want to take. My personal favorite is creating a line down the middle of each mountain, then you shade one half, on the opposite side of the light.

Unfortunately, I only have an example of the latter, but I hope I helped in some way.