The composition of your images is the most important factor in creating a successful shot and determining your very own style. A good composition establishes a sense of harmony between lights; lines balance, framing timing and the full range of Cinematography techniques. Of all the theories and mathematical formulae that have been expounded, perhaps the most recognized and most commonly applied is the rule of thirds.
The ancient Greek Pythagoras conceived of this equation that divides the frame into thirds both horizontally and vertically, and determines six points of intersection between these lines. These points of intersection are considered to be aesthetically pleasing points on which to have key elements of you composition placed or focused. So by carefully considering the placement of elements in your composition, the image will appear well composed.
I have tried to achieve just this with the Somber Sweetlips- Plectorhinchus unicolor; that I spotted hanging out above some corals by the North-west Buoy line at Koh Tao dive site White Rock. I swim around to ensure that the sun is at my back, this in turn helped to enhance the contrast and play of light on my subjects ventral and pectoral fins. I like to imagine that this fish is dressed in shining armor as the light dances from his scales.