The latest nest boxes I have made are from plastic totes...I really like these. I've lined them with cardboard to insulate them from the cold and heat, as they are outside the coop. I would normally have just built some from repurposed items or scrap lumber, but I wanted to try this idea for a coop I was building.
These were designed by cutting the bottom out of the tote, reversing it to use as a door that slides in a frame made of old tongue and groove flooring scraps we had lying around. It worked perfectly! Keeps out the rain and provides easy outside access.
A closer shot of the access door....
Here's one old hen waiting her turn for the "favorite" nest...while the other nest box sits empty. That's the nature of hens, so I just provide two nest boxes for a coop that is housing 9~13 hens. The front of this tote locks into place with the handles, so I used it for the front of the box, to make for easy cleaning out of the nests if needed by simply unlocking the handles and removing the whole front of the nest box. I cut the opening in the shape of an egg out of pure whimsy and for no other reason.