I've been drawing mountains today. Some say that mountains and trees are easier to draw than faces because you can get away with inaccuracies, and it's true that the worst draughtsmanship in my paintings are the mountains in the background that nobody would notice or care about. Even slightly mess up an eye though and everyone becomes an art critic.
In many ways drawing a mountain range, an ink blot, a screwed up ball of paper etc. is more challenging than drawing a figure or face. I've discovered that a useful trick is to see faces in them. Most people pick out faces in clouds and random patterns; the folds of the curtains contain lots of faces to me. The brain is better at processing faces than other images, and by seeing faces and parts of faces in shapes like mountains and folds you can more easily spot inaccuracies.