The so-called storage means that you can collect it, you can put it, and you are determined not to put it outside; What can be hung on the wall must not be put on the ground, and what can be put high must not be put down.
Buy a multi-layer shelf. I put a baby basin, laundry detergent, disinfectant, shoe brush and some things for bathing the baby on the shelf in the small bathroom. On the top floor, I also put a pot of green radish, which hangs down.
The cheap plastic multi-layer shelves on Taobao save a lot of space.
Many wall stickers, mop hooks and washbasin storage racks on the wall save space.
The photo is a wall of my small bathroom. You can hang everything on the wall for very little money. It's strong and won't fall off easily. It has been used for two or three months without any trouble.
Taobao also has a small storage rack attached to the wall, which can be directly attached to the tiles without punching holes and can hold many things. There is also a dedicated toilet storage rack, which does not waste any space.
If possible, you can install a washbasin with a storage cabinet, so that you can put toilet paper, toothpaste, toothbrush, cosmetics and feminine products in one more cabinet.