When I am walking through gardens, parks or woods, I Look for interesting subjects or textures to photograph. Sometimes I use them for the main image or backgrounds or textures for my ebooks to place images or text floating on top, giving a more visual look to the page. Here I was looking for interesting leaves & textures. Interesting skies and clouds also work well for this.
The above sunflower on the path is not backlie, but still an interesting background for floating images or a text block on the left side.