Here are the four different pictures that have a diagonal line as a main part of the composition.
1. The first shot was stairs that create a diagonal from upper left corner of the frame to the bottom right corner.
2. The second shot is a lantern with three rows of wires, that represent three diagonal lines. The lamp itself is also a diagonal. Here is also the problem of too sensitive ISO 1600, which creates a lot of noise. Also, the background could be more plain, because trees behind the wires are a bit distracting.
3. Though the horizon is horizontal, the shadow from the trees and the ski run show two obvious diagonals. And by cropping everything that was distracting the attention from them, I think I managed to create a 'diagonal' shot.
4. This picture I like the most, because of the composition and a big number of diagonals created naturally by the objects within the frame. This picture I have taken with a wide angle lens Tokina f.4 12-24mm. Out of four shots taken for this exercise, I like this one the most.