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 follows.
As you’re taking an image you would have done this in your mind through your viewfinder or in the LCD display that you use to frame your shot.
With this grid in mind the ‘rule of thirds’ now identifies four important parts of the image that you should consider placing points of interest in as you frame your image.
Not only this - but it also gives you four ‘lines’ that are also useful positions for elements in your photo
The theory is that if you place points of interest in the intersections or along the lines that your photo becomes more balanced and will enable a viewer of the image to interact with it more naturally. Studies have shown that when viewing images that people’s eyes usually go to one of the intersection points most naturally rather than the center of the shot - using the rule of thirds works with this natural way of viewing an image rather than working against it.
In addition to the above picture of the bee where the bee’s eye becomes the point of focus here are some of examples:
In this image they have purposely placed the head of the subject on one of the intersecting points - especially his eyes which are a natural point of focus for a portrait. His tie and flower also take up a secondary point of interest.
In this shot they have placed the subject along a whole line which means she is considerably off center and therefore creating an additional point of interest. Placing her right in the center of the frame could have resulted in an ‘awkward’ shot.
In a similar way a good technique for landscape shots is to position horizons along one of the horizontal lines also as they have done with the following shot (I’ll let you imagine the lines).
