I have to be tidy as my entire flat measures 24 sq. metres. I keep a lot of bedding in the long drawer under my bed settee - no airing cupboard, no utility room, just a narrow cupboard to house my vacuum cleaner and broom. My only outside space is the balcony, where I keep my sun lounger with a waterproof cover and large plastic storage crate. There is also a ski locker in a communal room on the ground floor, where I keep my snow shovel, cover for the car, wellingtons,spare petrol can, de-icer - no skis.
Oddly enough, apart from having to keep out-of-season clothes in bin bags in a wardrobe (I have just put my summer clothes back, after my six weeks in the New Zealand summer) I don't find myself short of storage. It is just a matter of being well organised (and having few possession)!