I use small plastic tubs like this.
My chickens love them.
They are about 5 in. deep and 9 in. by 12 in. across
I just set them on the floor of the coop and and fill them with shavings.
hope this helps
I have seen tubs,milk crates, and 5 gallon buckets used for nestboxes. I figured out to leave enough lip at the bottom of the entrance on the nest boxes to allow several inches of bedding in the nest or they won't use them.
More pictures of my coop so far
Igot a3x3 window to intall cheap.The hole at bottem right is for outside nest box. Dark side on left ontop are for vents the bottem one is for removable poop board
Went o a county fair took this picture of the chicken I would like to start with Colombian Wyandotte. I'm going to start the roof next.
Up date on my coop the roof is on except for the shingles .Hope to start the trim this week.I used a Wagner power painter with the stain It made easy work of it.
Vinnie