Painting well is a combination of many skills. Understanding colours and how to mix them, learning to be expressive with line and shape, to mention just a few. As students learn about composition, I encourage them to identify the large shapes in their composition. Squinting at the photo reference and painting in progress helps because this eliminates a lot of detail allowing large shapes to be more discernable. When there is a variety in the size of the main shapes, there is more likely to be a pleasing composition. These shapes should fit together in interesting ways, and perhaps people who do puzzles have an advantage here. They might more easily grasp the idea of shapes fitting into each other to form an image. In any case, making a quick sketch of the main shapes in your painting before starting can help you catch any major compositional errors before starting. Is there variety – some large some smaller? Do they fit together with interesting lines and angles?