The old-fashioned art of black and white photography went far beyond the initial picture-taking. Another, equally important creative process took place in the darkroom, where the image was dodged and burned to enhance the tones and concentrate the viewer’s gaze on the subject and composition. Dodging and burning is a bit of a lost art. […]
Vignette
Vignette effects can be very useful, both as an aid to composition and as a way of adding a vintage, 'analog' look.
A vignette can help focus attention on the main subject and tone down a distracting background. It can also act as a kind of framing device so that the picture feels properly enclosed and your eyes don't drift out of the frame.
Most photo-editing programs have a vignette tool. Lightroom, for example, has a 'post-crop' Vignette effect which adapts to any cropping adjustments you make, though its manually controlled Radial Filter is a more powerful tool for creating carefully customised vignettes.
With most vignette tools, you can choose the strength of the effect, its size, whether it's circular or rectangular or somewhere in between, and how smoothly it blends into the rest of the picture. Sometimes you can choose where to place the centre of the vignette too.