Hello, I'm new, hope you're well! :)

I'd like to make a bird box. I'd also like to use stuff that would otherwise go to landfill. I don't know what's the best/worst material though.

I'm told chipboard is bad, and plywood, as they swell up or have weird surfaces on, or something. I've seen them made of old "for sale" signs, presumably plasticky, and I could probably use proper wood too.

Any ideas or experiences? :) Any materials that worked surprisingly well? Any dos and don'ts?

Thanks in advance!