Some friends and I recently moved underground to build a base together. Since we had as much space as we could dig out and no reason to worry about how things looked on the outside, iv had a lot of time to work on some of the bases interior rooms.
Two of these rooms are pretty full of furniture and decorations as a result of this, my private quarters being one of them.
The other somewhat cluttered room is the bases common room. We recently put up a christmas tree which is taking up a lot of space in one corner. Otherwise the area is furnished for the base mates to talk and relax.
Despite being underground we were lucky enough to build close enough to a ravine to have some open space to landscape as an underground garden.
Lastly, we recently decided to make a separate storage room for our ores and enchanted books which I have also been able to work on the interior for.