I assess often. I have many reasons why, but that is for another time. To help grade efficiency I have rules about writing on one side of paper and leaving space for problems. I joke about helping an old man out with my students.
But what do we do when a student does not do it? Should we take points off for not following directions or for being insubordinate?
I don't - I grade math and work with the students for the next assessment. In the real world you often get chances to correct "format" things (and lets not kid ourselves school is not real world). And I don't agree that this type of instructions is about responsibility.
I write messages - a :( with a drip of water for a tear on a paper, or a message from a character - like a superhero or singer or a even just from a tree, like this:
While it is tempting to punish, my job is to teach.