Diagonal lines generally work well to draw the eye of an image’s viewer through the photograph. They create points of interest as they intersect with other lines and often give images depth by suggesting perspective. The ‘lines’ need not be actual lines – they could be the shape of a path, a line of trees, a fence, river or any other feature in an image.
In the above image there is both horizontal and vertical lines, and the repeated lamp posts running through the image.
Brown Leaf in Stream
For me personally, I much prefer shooting my diagonal line at the bottom right and moving to the top left of an image. Here, the leaf is at an angle to the stream and the rock that it is stuck on. Also, there is a diagonal line running down the center of the brown leaf. Finally, there are smaller lines branching off the solid center line moving up and out inside the leaf.
Some people shoot and prefer that the diagonal line that is traveling left to right, starting at the bottom left and moving to the top right of an image is natural. Hmm, not sure about that? What do you like or prefer?
Here is an example of converging lines, that is, two or more lines coming from different parts of the image to a single point can be effective.