When we moved into our house there was a small room under the staircase that my wife very cleverly converted into a linen cupboard.
To take it from room to cupboard we put up shelves to work with the contours of the space.
Adding the shelves instantly transformed the room and turned into a proper linen cupboard.
To take things to the next organisational level (there’s always another level) my wife recently purchased some brass tag and label holders from Amazon to mount to the shelves in a bid to label everything and make it easier to find the right linen and towels.