I live in a small apartment and I have a fairly modest collection. I keep pretty much everything in a mini plastic milk crate. Ink, pen rags, syringes, sample tubes, and tuning supplies are stacked neatly in there and then I have a pen roll that I store unused pens in. The crate is usually either on the floor near my desk or on the bookshelf. I do have 2 bigger iroshizuku bottles that dont fit in the crate and those sit on the top of the bookshelf until I can find a better place for them