Large shop windows backlight subjects standing outside them. Café windows illuminate faces from one side. The light from a window is directional, soft, and free.

Position yourself so the window light falls across your subject's face. Expose for the face. The window itself will likely blow out - that's fine.

Watch for: mixed light - window light on one side, ambient on the other - can create strong, dramatic shadow. This is usually a good thing.

Try this: Stand your subject side-on to a large shop window and meter for the lit side of the face. Let the shadow side fall dark for a free, moody split light that looks like a studio set-up and cost you nothing.

The point: natural window light makes portraits look expensive. It costs nothing.