Recently at a Photochrome meeting (San Francisco Imaging Club/society) a photographer showed an image of a person fishing at the edge of the ocean. In that image the fog was as thick as my recent day in Princeton, CA. A critiquing photographer suggested adding contrast to make the blacks truly black in the foggy seaside image.
But in my opinion, that alteration will diminish the true experience of the thick fog that came to rest at ground/sea level.
Substantial fog equalizes all the tones in its wake. Because of this an image could feel very flat or you could use it to convey foggy feelings. Here I did add a little contrast to the kayaker so he stands out from the gray marina.  Throw off the shackles of rules and expectations and create the images you want.
Even rusting chains on the ground have a story to tell. Some images and how they are processed are best not explained by their creators. Viewers, weave your own narratives.
See your mortal soul within and seize the world beyond!-sb