I have Orpington chickens and Guinea fowl. Both use the same nests most of the time. Mine are the large size covered cat litter boxes, the plastic ones with removeable top. I take out the swinging plastic door.
Then I put a layer of kiln dried shavings, then I make a bowl of hay over that. Then I sprinkle a little more shavings into the bowl on some. On some I leave the hay bowl bare with just shavings underneath. Some of the hens like one set up, some the other. Over all of this I dust DE. Sometimes on the bare floor of the nest boxes I'll sprinkle permethrin, finish off with the DE. We don't have any lice or mites but I do this anyway for precaution. Some of the guinea hens will make bowls in the areas of the barn having dirt floor or hay-covered floor. They do a good job building the nests with hay themselves. These are the Guinea hens who want to start a clutch.
Heritage Hens