Portrait composition in photography is really not that much different from picture composition in art or even subject composition in general.
It just requires an awareness of the principles in the first place, and once the guidelines are part of your thinking, they will become second nature to you.
Then you can trust to your instincts and strong composition will come naturally to you. Think of these portrait photography rules of composition as guidelines rather than absolute rules, and let them help you develop your innate sense of design.
The first of these tips looks at how to position your subject. Most people place the subject right in the middle of the frame but try something a little different next time.
Above: Author Bill Kirton by Anne Darling
In the photograph above, I have purposefully chosen to place my subject off-centre. This gives a more dynamic feel to the composition but just as importantly we can see some context in the background. Including the background gives context and information about your subject, such as where they live or work.
Above: Caged Bird (Shaoxing, China) by Anne Darling
In the Caged Bird image (yes, it is still a portrait!) my subject is again off center and you can see that the shot was made in China where there are still many people who keep caged birds. Often they place the cage outside the house to let them see the world passing by or take the cage to the park to meet with other people who have caged birds. In this way, the men and women get to meet up and chatter and so do the birds!
If there are areas of interest in the background that you wish to include, be sure to choose the highest number f-stop so that the depth of field is maximised. That way you will have uniform sharpness and everything will be in focus. In this image I have used an f-number of f/4.5 so the depth-of-field is a bit shallow and has given a soft blur to the sign with the Chinese characters. The portrait of Bill Kirton however has an f-number of f/11 so there is more detail in the background.
One of the most basic portrait composition tips, without using any equipment out of the ordinary, is to place your subject within a natural framework such as a doorway when creating formal and informal portraits.
Using a frame in this way helps to keep the eye within the photograph as well as presenting your subject well.
Above: Canalside Dweller (Shaoxing, China) by Anne Darling
If you are using a doorway, try to balance the exposure to include some of the detail in the interior. If it looks too dark in the final photo you may be able to adjust it in post-processing. Don't overdo it. The viewer doesn't need to see the interior as clearly as the exterior, it's just to give a flavour of what's inside, a hint at how your subject lives or works.
In the image below, the subject is a Chinese boatman using his feet to steer as is the tradition with this kind of boat called a sampan. The subject has been 'caught' within the frame, and the composition is also enhanced by very strong lines both diagonal and horizontal.
The straight lines within the photographic composition are balanced by the curved arch of the sampan. Geometric shapes can be pleasing to the eye if positioned well.
Above: Sampan Boatman (Shaoxing, China) by Anne Darling
The technique of framing is an important one in portrait composition, and because of this I have written a second article on the topic with some beautiful examples by various photographers - just follow the link if you would like to read more on this useful technique.
Find out more about portrait composition on Amazon. I particularly recommend the two books below as both receive high ratings.
A photographer's guide to making meaningful portraits of the modern family
Techniques and Images from the Pros