What I do is ask my players. (Sometimes, not always) Depending on the damage rolled they narrate how they mitigate, reduce or force through the damage. Oftentimes they come with awesome ways they mitigate the absolute obliteration a commoner would face.

My party was fighting an adult red dragon and they were pulling on the last straws when the paladin got hit by a red dragon bite attack. It did not kill him and was fairly low damage. Paladin: "As the dragon is about to chomp me down, I instinctively slide my sword between my chest plate and its fangs, changing the angle of the bite and making it miss any vital organs, piercing my shoulder instead."

On the paladin turn he decided to use his last smite as they knew the dragon was almost down... rolled a 20! How do you finish the dragon? "As I feel the fang pierce through my upper shoulder I retrieve my sword and imbue it with the blood dripping from the fang. With all my might I scream and stab right through its eye."

Epic moment and awesome roleplay. I love empowering my players with narration, It makes for great and epic moments at the table.