Ammonite fossil from Madagascar (© ThomasLENNE/Shutterstock)

Leshan Giant Buddha, Sichuan, China (© www.anotherdayattheoffice.org/Getty Images)

Using grid lines is a flexible and powerful way to place your elements on a grid, but, when looking at the code, it might be a bit hard to visualize.

Harbor seals at Robert Moses State Park, Long Island, New York (© Vicki Jauron, Babylon and Beyond Photography/Getty Images)