Hi Gary,
First of all, welcome to
RP.
Had a go with your image. Did'nt want to make the difference between hair and background too great as it would upset the lighting of the shot.
I first copied the background to a new layer. Then applied a levels layer, linked to the copied layer and used it to emphasise contrast as much as possible. Then I used extract filter to isolate man from background. Cleaned up the extraction a little using history brush and eraser.
Now dispose of levels layer, and set blend mode of copied layer to multiply. Reduced layer opacity to about 20%, then applied a graduated layer mask fading from white at the top of the man's face to black at the bottom.
Finally cleaned up a few minor blemishes with clone tool, and ran through Neat Image to reduce noise.
Hope this helps.