I will say right up front however that rules are meant to be broken and ignoring or breaking this rule doesn’t mean your photographs will automatically be unbalanced or uninteresting. But if you are going to break the rules it's alwys better to know what the rules are in order to ascertain whether your photograph will benefit.

Grid demonstrating the rule of thirds.

What is the Rule of Thirds?

The basic principle behind the rule of thirds is to imagine breaking an image down into thirds (both horizontally and vertically) so that you have 9 parts. as can be seen in the picture.

The theory behind the rule of thirds is that if you place elements of interest in the intersections or along the lines that your photo becomes more balanced.

Various studies have shown that when looking at photographs that people’s eyes naturally go to one of the intersection points rather than the center of the shot - using the rule of thirds works with this natural way of viewing photographs rather than working against it.

Placing the primary subject at intersecting points of the grid.

In the photograph the picture demonstrates the positioning of the grid showing the point of interest  where the lines intersect, creating a more interesting photograph than would be achieved by simply placing the subject in the middle of the scene.

Don't worry too much about getting this right on the day, today's photo editing packages provide cropping tools which will enable you to crop your image to suit the rule of thirds, try experimenting with existing photographs by framing or cropping them to the rule, I am sure you will be suprised how your photographs suddenly appear to hold more interest.

I hope this tip helps you to get a little more out of your photography.