Silhouette

Shoot images where subject is silhouette and put in an album titled: Silhouette
Compositional Focus:
Often it is best to underexpose the image. The tutorial below explains this.
Number of images: 15
Sample Images
Video Explanation:
Here is a video that explains how to use exposure control in the native camera app for an iPhone to create a better silhouette. Other smartphone native apps may have a similar feature.
Here is an AP Sustained Investigation about Silhouette: