DIY bondage Bed Ideas

I’m searching for concepts on building my own bondage bed; I know they are available online, but that’s not what I want. Preferring to DIY it instead. Got any suggestions or advice?

Is sleeping on it important? Does it need to look normal? Ours is a divan style with six "feet," each having chain fitted with snap-links. There's also another chain running between the feet at the headboard end, featuring a centre ring. This setup supports spread-eagle positions and many others, making it easy to add more chains or ropes. When not in use, you can just kick the chains under the bed. If our curious grandchildren visit, we remove them easily and hide them inside drawers disguised as plinth fronts beneath fitted wardrobes, right alongside most of our "toys".