Take a number of shots using lines to create a sense of depth. Shooting with a wide-angle lens (Zooming out) strengthens a diagonal line by giving it more length within the frame. The effect is dramatically accentuated if you chose a viewpoint close to the line.
It is surprisingly easy to find lines which add depth to an image. I think the overall effect is achieved not only because your eyes are drawn along the lines and into the distance but because it makes the person viewing the image feel as though they are looking into the image. It represents a ‘real’ image that the brain can relate to, they are / can feel part of the scene. Interestingly I find that the most successful of these ‘real’ images would be where the perspective line meets the horizon or imagined horizon. The shot I took with the mirror reflection line is interesting as your eyes follow the intended path but there is no natural horizon so I find my eyes scanning the scene, I wonder if this is because the brain is trying to make sense of the ‘quirky’ horizon.