The aid of an assistant is useful for this technique, as it involves positioning a softbox above a subject and angled down towards them. Trying to do this yourself is difficult and the angle means a lighting stand isn't suitable – although a boom is an option should you have one.
To light effectively, you want to place it at a height that illuminates the subject while allowing as much of the area around them as possible to fall away into darkness. Try setting the zoom head on my flashgun to 70mm to minimise the spread of light, before fitting a 70cm softbox to give a soft yet focused light. My softbox of choice for this effect is the Lastolite Ezybox as I've found its bold edge gives a very attractive fall-off of light that produces a very attractive vignette.
One thing to watch out for when shooting close to walls or polished surfaces are flash hotspots. Sometimes you can adjust your position or that of the softbox to eliminate it, or crop the image to exclude it. Occasionally you'll need to remove it in post-production.
1 The set-up for this is simple as only one light is used. Start by angling a softbox above the subject.
2 Set the flash sync speed and choose your preferred aperture – I chose f/11. Fire some test shots. Note whether the image is too bright (as in this case) or too dark and make adjustments to the flashgun's manual power settings. Also move the position of the softbox to ensure an attractive spread of light! Here you can see what it looks like with too much flash (below left) overflowing on the backdrop and just the right amount to focus in on the subject's face (below right).
3 With exposure sorted, concentrate on poses. Having our model's face turned slightly towards the light ensures it is free of unattractive shadows. Have your subject try different poses to see what works.
4 As well as holding the softbox above the subject, try it at a lower angle as this illuminates one side of the subject and throws the scene into darkness.
5 Using a single light source in this way close to the subject isolates them from the background, giving a polished and professional result.
A special thank you to Brett Harkness Photography for providing the expertise and images for this tutorial.