Nothing brings out a good gurn like the concentration on a spicily-positioned crux.
It requires determination from the photographer, as often the premium gurns are pressed close into unyielding rock, or visible only to the sky as leaders strain upwards.
The subject too must have the right sort of face - sufficiently pliable to be contorted into a mask of concentrated effort and fear.
There must be some belters. Where are they?
To get you started:
https://www.ukclimbing.com/photos/dbpage.php?id=260573