Our eyes love to examine and compare textures. Eyes like visual repetitions. In a sense, it is a more involved version of framing. Helps structure and layer the image to create separate pictures within the larger one. Other compositional suggests.
Composition works best when a combination of devices or strategies are used together.
Composition can be learned. Best photographers and artists have an inner sense of composition, but clearly, it can be easily taught. Normally, don't have photos looking off page. When using a series of images, it's important to allow one to dominate. Also, where you are presenting a number of other images, grouping is a good strategy.