How do you draw the front of a cliff?

How do you draw a simple rock?

Step-by-Step Instructions for Drawing Rocks
  1. Begin by drawing a bumpy, curved line.
  2. Enclose the figure of the rock using a second irregular, curved line.
  3. Begin to draw another, smaller rock using a curved line extending from the first.
  4. Finish enclosing the figure of the second rock using a curved line.

How do you draw a landscape?