Rules of Composition: Rule of Thirds
I probably use this rule of composition more than any other. It’s the rule of thirds.
It isn’t a hard and fast rule; it can just make your compositions more interesting.
The idea is to mentally divide your image into 3 sections and either put your subject close to the intersection of those lines or, if you’re shooting a landscape, assign the different elements of your scene to fall on the one third or two thirds lines.
Putting your subject on the intersection of the lines doesn’t have to be precise, it can just fall in the general area.
The water in this beach scene takes up the bottom third of the image, and the sky fills up the top two thirds of the frame. The heron falls close to the first one third vertical line.
Sometimes you have to take other elements into account as well; for instance, I wanted the bridge to look symmetrical, so my beautiful subject doesn't quite fall on the intersection of the lines, but the composition is still pleasing.