Welcome to Backyard Chickens!
There are many great options just depends on your chickens and your setup.
I have a small coop I plan to use for my silkies. No laying boxes in it, so possibly will use milk crates or buckets.
Welcome to Backyard Chickens. This is a great place to explore and hang out. I use plastic storage boxes with the front cut out.
Easy dremel did the job.