Pattern. Repetition. When you hear these words, what springs to mind? Maybe a print dress or possibly wallpaper for the former, and likely a sense of ennui for the latter? The words themselves do not necessarily evoke any sense of excitement or anticipation. The prospect of shepherd's pie for supper, every night, for the rest of your life is certainly not the kind of repetition that sets the mouth watering. But the senses are, actually, rather fond of both pattern and repetition. The ear appreciates rhyme, assonance, and alliteration. The eye favours rhythm, flow, and stability, too. By introducing them to your compositions, you have the opportunity to create appealing, compelling images.
Pattern hunting
The act of deliberately watching out for patterns to photograph might feel a little, or even a lot, contrived, but once you start you might find it a little difficult to stop. Patterns present themselves both organically and synthetically, from flower petals and fruit peels to tyre-treads and architectural work.
Get in close or shoot from far away; come down low or climb up high and you can pick out patterns wherever you are.
Consistent patterns
By isolating a pattern from its background, it's possible to imbue it with a sense of the infinite. With no evident beginning or end, for all the viewer knows the pattern extends interminably. Creating this sort of indefinite image is relatively easy: identify a pattern and get in close using either a telephoto or macro lens. By adjusting the aperture of your lens, you can choose a shallow depth of field with the pattern blurring into infinity, or one that's sharper across the frame.
Broken patterns
Spot a break in a pattern, make it the focus of your image, and you have a great photo. Look for the red apple in the pile of green, the solitary shoe facing in the wrong direction on the shoe stall at the market, or the silk scarf in the row of woollen ones. Wherever there is an aberrance in a flow, there is a photo.
Pattern and colour
If you've decided to fill your frame with a single colour, or variations on a particular colour, you might find that it's patterns that give the photo interest.
Composing for patterns
You'll often find that the constituent parts of the pattern create the compositional imperative for your photo: lines will point in a particular direction and dictate frame orientation or an aberration in a row will set a natural point of focus.
What you need to do is use these indicators to create tension and balance in the frame. Try setting the point of focus off-centre—think of the rule of thirds—and angling lines on the diagonal to prevent them from presenting as flat or confrontational.
Most important is to be certain of what you are trying to convey in your photo—from the feeling of the infinite, the odd one out, to the sense of consistency—to design the strongest image possible.
Remember: pattern and repetition does not have to be boring.