You can use any type of lines or shapes in your composition. Just be aware that we are trying to make it relatively easy for the viewer’s eye to move around the composition. If we jam diagonals into other shapes, or create visual walls, we may block this journey. It is important to be able to control this, so you can control the ease with which the viewer’s eye moves around the painting. There may be a time when you want to visually hold the viewer’s eye in one place.