Occasionally we need to run a picture in black and white. With most shots one can tell at a glance that the picture will convert to BW just fine-- it'll "read" easily. But there are a few that need help to become readable in BW. Here's a straight BW conversion of a construction picture:

The fencing, machines and guy all stand out in the color version, but are nearly lost in the BW. In this case, the fix is easy: what makes those items stand out in the color version also make them stand out to the magic wand tool in PhotoShop, so the selection of them is easy:

The next step is to brighten the selection with a control such as "levels", "curves", or "brightness/contrast":

The picture now looks a bit strange in color (above), but when turned into a BW, it looks fine. Here's the final, with the earlier BW for comparison: