When you are composing your photograph have in mind the principles of the rule of thirds. This rule suggests that you draw an imaginary noughts and crosses board over the photograph that you are about to capture. Where the lines intersect is a good place to position the subject of your image.
For example, if someone’s eyes are located where the lines intersect you will get a much more interesting photo than if the person is positioned dead centre of the photograph.
In addition, placing the horizon along one of the lines of the noughts and crosses board is more interesting than placing it across the middle of the photo.
Simply moving your camera a little bit to the right or left, or up or down can be the difference between a so-so image and one which looks much better.