Pencil is a great medium for those times when the weather is changeable but I still want to work outside. I can concentrate on line rather than light and shadow, and still plan out compositions for later paintings.
When I teach drawing, I like to devote one entire class to drawing boxes in perspective. I get a real kick out of seeing everyone improve their observational skills simply by holding a pencil up vertically or horizontally to check angles, and trusting what they see. Drawing houses is not any harder than drawing boxes. You get the first one right, and the others will follow.