According to Loomis in "Successful Drawing," the appeal of a drawing involves several factors. Among those factors are The Five P's.
Loomis believes that a drawing's appeal for a viewer is encompassed in "intelligent perception," vision coordinated with the brain. The human brain simply knows when it's looking at something that works and is attracted to it while being repulsed by that which doesn't work (the uncanny valley.) It's important for artists to be aware of the viewer's intelligent perception to ensure that our work gets the intended response. These are a few basic elements to a good drawing and those elements can be learned.
Let's start with The Five P's:
1. Proportion—every object has height, width and depth. The ratio among these three dimensions is proportion. When the ratios are correct, the drawing looks good.
2. Placement—the positioning of the object within the boundaries of the drawing area.
3. Perspective—the object's relationship to the eye level/horizon. No object can be drawn without perspective.
4. Planes—in order to correctly show an object's light, halftone and shadow, the object must be divided into planes. The effect of light on planes makes a form appear solid.
5. Pattern—the overall tonal arrangement of a composition.