Creative Image Editing in Photoshop - Black and White in Photoshop CS4 and Photoshop Lightroom - page 222

Try this technique with portraits!
To blur the background, repeat Steps 1-3 then choose Filter menu Blur
Gaussian Blur to soften the edges.
Correcting Exposure Issues with Adjustment Layers
If you have an image that is a little over- or underexposed, then there is no
need to worry - a quick and simple adjustment in Photoshop will have your
image looking like it was correctly exposed in no time at all.
Create an adjustment layer for Levels or Curves with the Adjustment panel, or
with the adjustment layer icon at the bottom of the Layers palette. I usually
choose Curves. or go to the Adjustment Panel New Adjustment Layer
Curves.
Do not adjust.