In one of the LinkedIn groups I follow, Davesh asked for help with this image taken with, I am guessing, a cell phone camera with a dirty lens:

 with a couple of minutes in Photoshop (or any other retouching program)

I found the original a bit pasty an flat, in addition to the light flare from the dirty lens, so the first step was an overall contrast and saturation adjustment.

Next I tackled the faces covered with flare. I simply made another curves adjustment layer, matched the tone of the “flared” area to the unflared area, then masked off everywhere else.

Last step was to darken the background. Again I used a curves layer with a mask to control what was adjusted.

As a final last step, I was not happy with a couple of the faces, so I touched them up a bit more.

All in all, it took me much longer to write this description than to retouch the photo. Yes I could fix the photo quite a bit more. There is a lot of fine tuning I could do, but sometimes a quick “down and dirty” job is good enough…

PS. One of the responses in the above discussion mentioned that the background light is distracting. I agree, but removing it with the clone tool for example was a bit more work than I was willing to put into the image. Another poster had a better suggestion anyway, just crop off the top… makes a better composition anyway…