At Christmas, I was at my girlfriend's country house as well. Later in the evening, we went to see the coast where the massive cliff is. Outside there was a very dense fog and basically you couldn't see anything. The drop of the cliff seemed bottomless. Soon I realized I can cast shadows on the fog when flash lighting with a phone behind the camera, I decided to improvise a little.

This is me in the fog. Taken with 30-sec shutter speed.

As you can tell, this is my hand.

And this is a tripod.

We came back to the same place in the morning as well. There was still fog but not so dense anymore. I took some more photos at the location.