RULE OF THIRDS
The rule of thirds involves mentally dividing up your image using 2 horizontal lines and 2 vertical lines, as shown below. You then position the important elements in your scene along those lines, or at the points where they meet. The idea is that significant compositional elements be placed along imaginary lines that break the image into thirds, both vertically and horizontally. Elements of particular interest can be placed at the intersection of these lines, for a more expressive and dynamic composition, as demonstrated in image below