Rule of thirds is the process of placing two equally spaced vertical and horizontal lines across the photo – thus creating nine squares, looking like a Tic-Tac-Toe board. You can have this overlay on the screen of your iPhone and Android smartphone. It does not record on the photo!

Why use the Rule?
When you position the main subject in the centre of the photo – it becomes static. The viewers' attention goes straight to the centre of the photo and gets stuck there. Imagine now, a photo of a subject positioned off-centre. The viewer is then encouraged to look beyond the main subject and further explore the remaining photo. This is where you can position supporting subjects and/or background to provide the context and narrative to the photo. The subject can remain the dominant object in the photo, through the use of size, lighting, colour and sharpness.

You are already doing it!
You probably already do this without realising. Have you taken a photo of someone (or selfie), where you want to show people or remember the context of where you are. You will no doubt already be placing them in the side of the frame, or at least ensuring there is enough space around them to see the context of the location.

Four intersecting points
The ideal position is actually atop of one of the four points where two lines intersect. This places the subject off-centre both vertically and horizontally.

iPhone: Open the photo in your Photos app > Edit > Crop (crop icon with arrows) > Aspect (the stacked square) > Square. Drag the image and/or each corner then tap Done.

Samsung Android: Open the photo in the gallery > Transform > Ratio > 1:1. Drag the image and/or each corner then tap the tick icon.

How do I crop an image using Snapseed?
Snapseed is my favourite mobile photo editing app. Cropping the photo is step two in my six-step 'Simple Snapseed photo editing process' article

Open the photo > Tools > Crop > Square.

The Snapseed app provides a Rule of Thirds 3x3 grid overlaid on the image. Drag the image and/or each corner then tap the tick icon.

Portraits
Next time you see a magazine cover – notice the model's eye will always be in one of these four intersecting points. It will also be the eye closest to the camera. Sometimes there may be variations when the photographer has to leave extra room for text and headings on a magazine page. This also applies to taking portrait photographs of your pets!

I have had a couple of attendees contact me several weeks after an in-person smartphone photography workshop – to tell me that I had ruined going to the movies forever! Now they find themselves analysing the production and positioning of the actors and are now seeing the rule of thirds everywhere! You probably will too now – you're welcome!

Which line do I place the subject?
Now imagine a photo of a person positioned ideally on the left of the two vertical lines. In the first photo, we have the person looking toward the middle of the photo. This allows us to see what they are looking at and quickly interpret the story being communicated. In the second photo, the person is positioned the same – however, they are positioned on the right vertical line and looking toward the edge of the photo. This can create some visual tension, as we cannot see what it is they are looking at. It creates some unease, confusion, mystery and in some instances can completely change the mood.

Although the viewer is encouraged to use their own experiences and imagination to interpret your image – you had a clear intention for taking the photo. Cropping the image without sufficient considering can dramatically change the story, look, feel, mood and emotional response from the viewer.

Square photos rule of thirds variation
On the iPhone – you have the option to capture a square image as a capture mode. Most Android smartphones have multiple aspect ratios available in the settings.

When you either capture or edit a photo in a square aspect ratio 1:1 – the rule of thirds stills applies. However, the lines closer to the middle are not that far off-centre. I recommend imagining the interesting lines further out. This creates more space that is normally a bit of a struggle in a square photo.