All objects have a history, how they were used, who made them, for what purpose, why were they discarded? Where has that stone, shell, piece of metal, shard of glass or ceramic been and how did it get there? Who used that piece of jewelry and how did it get broken? What is that leaf, piece of wood, seed capsule? I think about these things when I am working on a piece.
I like to use cast-off things because non cast-offs are still in use so there is no question to ask.
I combine these things intuitively with no message in mind. It is left to the viewer to see from their own perspective.