It looks like you have a nice setup for nesting boxes! I would get rid of the trays and just lay bedding or straw in the enclosures. If you change this frequently it should stay pretty clean since the bedding will absorb any droppings. I would also clear out the stuff in front of the boxes so that it is easy for the hens to get to the boxes. I would also make sure you have food and water nearby (easily accessible). Good luck!
