A simple principle but powerful technique
The rule of thirds is a simple principle but powerful compositional technique for making photos more interesting.
As you can see on my photos showing here, I always use the Rule of Thirds for my guidelines to Composition.
When I use the rule of thirds I will imagine the grid (nine equal squares) on my mind and then place the strongest subject or focal points into the four points where lines intersect. If your smartphone camera has grids, this should be much easier.
By doing so I can make my photographs more interesting even I took it with Smartphones.