One of the easiest and fastest ways to improve your image whether it be in a formal portrait or even in a facebook or instagram shot is the "Rule of Thirds". It's easy and improves your image big time!
Photographers use the rule of thirds as one of their most useful composition techniques. It's an important concept to learn as it can be used in all types of photography to produce images that balance out the subject and better engages the viewer. Artists use it all of the time!
Of course, rules should never be applied blindly, particularly in art, so you should think of it more as a handy "rule of thumb" rather than one that's set in stone. But it makes a better photo more often than not, and is an excellent starting point to compose your image.
So what is this rule of thirds?
Start of by mentally dividing up your image using 2 horizontal lines and 2 vertical lines, as shown above. Once you choose the main element in the scene (like the small cabin in the picture above), you position that focal point along those lines, or at the points where they meet. Not only is the cabin in the intersection of the these points, also notice that the snow on the ground also stays in a third of the picture.
In landscape shots, most people tend to position the horizon along the center of the frame. Instead, place the horizon line along in the third area and see your shot improve dramatically.
The idea is that an off-center composition is more pleasing to the eye and looks more natural than one where the subject is placed right in the middle of the frame. It also encourages you to make creative use of negative space, the empty areas around your subject.
You can use this technique in portrait shots as well. As you can see in the portrait below, the models faces are in the third area of the image. In portrait photography, the eyes are the crucial focal point that makes or breaks the image... those gorgeous smiles help too!
When photographing moving subjects, position them as normal, but also pay attention to the direction they're moving. As a general rule you should leave more space in front of them than behind, to show where they're going.
As with all rules (at least in photography), the rule of thirds doesn't apply in every situation, and sometimes breaking it can result in a much more eye-catching, interesting photo. Experiment and test out different compositions even if they go against any "rules" you've learned. And there you go... a great tip to make your shots even better! Keep shooting!