TELL A STORY WITH EACH GRAPH!
As you start to build your debris graphs think about how each object might have aged over time in this environment. Instead of building objects that are pristine, try to make them damaged and worn. Bottles and cans become dented and crushed. Plastics break and fade. Wood on the beach becomes more rounded and cracked. If this debris pile has been here long enough then it might be sun-bleached or have barnacles growing on parts that used to be submerged. All these details add up to create a much more believable material.