Create a Smart Edge Vignette in Photoshop

Photoshop can add a soft, darkened edge around any photo in mere seconds — an effect known as Vignette. Choose Filter> Distort> Lens Correction, then drag the Vignette slider all the way to the left. To darken the edge color even more, grab the Midpoint slider and drag it slightly to the left.

For a non-destructive approach, use a Smart Filter:

With an open image, choose Filter> Convert for Smart Filters, and then choose Filter> Distort> Lens Correction. In the resulting dialog box, drag the Vignette slider all the way left. To increase the vignette width, drag the Midpoint slider slightly to the left.

You can also use the Smart Filter mask (big white thumbnail below your image layer) to hide the vignette from your subject’s face (just paint within the mask with black).

To lower the strength of the vignette, open the filter’s Blending Options by clicking the tiny icon to the right of the Lens Correction layer and then lower the Opacity setting.

An advantage to this approach is that the vignette resizes itself if you crop the image!

(tip courtesy of Lesa Snider’s Photoshop CC: The Missing Manual)