Shoot exclusively in black and white for one month. If your camera has a monochrome mode, use it so you see black and white on screen while you shoot, not colour you'll convert later.

The purpose is to change what you notice. Colour is a massive source of information — and distraction. When it's removed, you start to see light and shadow, texture, tone, shape. Subjects that seemed interesting because of their colour become boring. Subjects you ignored become striking.

By day ten you will start to pre-visualise in black and white. By day thirty you will have a different relationship with light than you had at the start.

Watch for: the temptation to shoot the same subjects you always shoot, just in black and white. The month should change what you photograph, not just how it looks.

The point: black and white is not a stylistic choice. It is a way of seeing.