The shelves are the design decision here, not the closet. Depth, tilt and clearance are what make a run like this hold twice what it looks like it should.
Almost every small closet I have been asked to fix has the same problem, and it is not that there is too much in it. It is that the shelves are the wrong size.
Shoe storage is where this shows up most obviously, because shoes are the one category that refuses to behave. They do not fold, they do not stack, they come in wildly different heights, and nobody throws them away. So they end up in a heap on the closet floor, which is the least efficient thing you can do with that space. A dozen pairs in a pile occupies roughly the footprint of a small chest of drawers and blocks access to everything behind it.
The fix is not more storage. It is correctly proportioned storage. And proportion, in a closet, comes down to three numbers.
Shoe shelf depth: 12 to 14 inches, not 16
A standard reach-in closet is built around 24 inches of depth because that is what a hanger needs. Most people then run shelves at the full depth of the box, which is where the waste starts.
A women's shoe is roughly 10 to 11 inches long, a men's closer to 12. Give a shoe shelf 16 or 24 inches and the back four to twelve inches becomes a dead zone, too shallow to hold a second row you can actually reach, deep enough that everything migrates backwards and disappears. Twelve to fourteen inches is the honest number for everyday shoes. Boots and larger men's sizes want 15 or 16, so if you are building a run, give the bottom bay the extra depth and keep everything above it shallow.
What you do with the depth you claw back matters more than the inches themselves. A shallower shoe run leaves room in front for a drawer bank, or lets the shelves sit under a hanging rod without you having to duck around them.
Vertical clearance: 7 to 8 inches, and a taller bay for boots
The second number is the gap between shelves, and it is the one people get wrong in the other direction. Too generous, so a closet that could hold six rows holds four.
Flats, loafers, sneakers and low heels want 7 to 8 inches of clearance. Ankle boots and high-tops want 10 to 12. Tall boots want 15 or more, and they want it in a dedicated bay rather than a general one, because a boot laid on its side in a 7-inch gap crushes and blocks the two pairs next to it.
Make the shelves adjustable if the system allows it. Wardrobes change. The one thing you can be certain of is that the shoe collection you have in five years is not the one you are designing around today.
Tilt the shelves. This is the free one.
The third adjustment costs nothing and almost nobody does it.
A flat shelf shows you a row of toes. A shelf tilted slightly toward the front, even five or ten degrees, with a small lip or a length of dowel to stop anything sliding off, shows you the whole shoe, upper and all. You can see what you own at a glance, which ends the daily hunt for the second one, and because the shoes sit at an angle rather than flat, you fit more pairs into the same run.
Tilted shelving is the difference between a closet that stores shoes and a closet that displays them. And there is a real case for display: a well-edited shoe collection is genuinely lovely to look at, which is the argument I made at length in the art of the edited closet. Shelves at the right angle are what makes that possible.
Where the shelves go when the floor is already full
Three places in almost every bedroom sit empty, and all three take shoes.
Under the hanging rod
Shirts and jackets need about 40 inches of hanging length. In a rod set at standard height, that leaves well over two feet of air beneath the hems, running the full width of the closet. It is the best shoe location in the room: zero additional floor space, everything hidden behind a door, and the shelves are at a height you can actually see into.
If the closet has one rod and one shelf, it is working at about half capacity anyway. Adding a second rod, a bank of shelving down one side and a shoe run at the bottom roughly doubles what the same box holds. That is the argument for a properly planned custom closet design over a stock fit-out. Not the cabinetry finish, but the fact that rod heights, shelf depths and drawer positions get set against what you actually own and which way the door swings. Same square footage, considerably more in it.
Under the bed
The largest unused volume in a small bedroom is under the mattress. Low-profile trays on castors work better than boxes here because you can pull them out one-handed, and if the frame allows risers you double the clearance at no cost.
Keep this for off-season pairs only. Anything that takes effort to put away does not get put away. It ends up on the chair, and then the chair is gone too.
The back of the door
A bedroom or closet door is six feet of flat vertical surface doing nothing. An over-door rack holds ten or twelve pairs and costs you no floor at all.
It is not beautiful. I would not put one on a door you see from the bed. On the inside of a closet door, where it is only visible when the door is open, it earns its keep. Worth thinking about alongside the doors themselves, because bifold and closet doors behave very differently here, and a bifold gives you almost nothing to mount on.
Apply the same thinking to the rest of the room
Once the shoes are off the floor, the same logic scales up.
Most people stop storing at about five feet and leave everything above it as air. Put a second shelf above the existing closet shelf for luggage and spare bedding. Run a floating shelf over the door frame. Swap a wide low chest for a tall narrow one, since a five-drawer tallboy holds close to what a six-drawer wide dresser holds in half the floor area. Move the bedside lighting onto the wall so the nightstand stops being a landing strip.
And make every large piece do two jobs. A bed with drawers in the base replaces a chest of drawers. A bench at the foot of the bed is a seat and a blanket store. If a piece of furniture in a small bedroom only does one thing, it is not paying its rent. There is more on this in maximizing small spaces, and on containing the loose things in organizing with storage boxes.
The numbers, in one place
Twelve to fourteen inches deep for everyday shoes, fifteen or sixteen for boots. Seven to eight inches of clearance for flats and low heels, ten to twelve for ankle boots, fifteen or more for tall ones. Tilt the shelf five or ten degrees and add a lip. Put the run under the hanging rod before you put it anywhere else.
Houses should be lived in, and a bedroom you have to pick your way across is not being lived in, it is being negotiated with. Getting three measurements right is usually the whole fix.
