A good technique to learn is the elements that attract the viewer’s eye first. These will help you draw your viewer’s attention to your subject
(and avoid your subject being overshadowed by another part of the photo).
Here they are:
Eyes: Human beings are programmed to look at eyes first whether they are people or animals. So if your subject is a person or animal, make sure the eyes are sharp.
Areas of brightness: The viewer’s eyes will ALWAYS go to highlights before darker areas. So if you picture has a very bright area that is not the subject, Recompose, or the viewer’s eyes will not be drawn to the subject but the bright area. (also a good tip to use to draw the viewer TO your subject).
Sharpness: The human eyes always resolve on areas that are sharper and in focus and will move away from out of focus areas. Blurred areas are not comfortable for the eye to sit on, and will force the eye towards the sharp areas. A good example of this is portraits with blurred Bokeh backgrounds, which force the eye onto the in-focus subject of the person.
Colour against a monochromatic background: Placing a brightly coloured subject against a background of a single colour is an excellent way to highlight your subject. The viewers eye will automatically find the monochromatic part bland and want to resolve on a subject; a great way to guide the viewers eye.
Areas of High contrast: The point where darker elements meet with lighter elements is a natural eye attractor. It is a key part of why silhouettes work so well. However this can be used in many types of photographs to draw the viewer to your subject, not just in silhouettes.
Complimentary color: Use complimentary color to add a wow factor to your image. All colours have an ‘opposite’ contrasting colour. These colours really thrust your subject forward when placed against each other as ‘subject’ and ‘background’. It forces the viewer’s eye to your subject.
Example Complimentary colorrs
For a video tutorial on these 'Eye Attractors and Distractors' go here:
Perfect Photography Composition - Part 2 of 8 on Vimeo