Thanks! I should have been clearer in that the litter box isn’t in the closet itself — just the room. I’d hate to have to climb into the closet every time it needed to be cleaned which is often with 2 kitties - ha.

I think it's much easier to use a deep storage closet when you can walk in without having to remove anything from the floor, and then remove things from shelves. So a few shelves would be a good addition.

Make it the litter room. Cat door cut into the door. A nice private bathroom for kitty.

If that is an access panel in the back, you need to keep any shelving removable.

Always buy clear plastic storage units. I would measure that shelf on left and get clear plastic drawer units that can be stacked up. They would enable pulling out drawers to get access easily. Get the big plastic containers out of there. Leave enough space on top of drawer units for your workout ball. Add small pull out rod for hanging a few guest items when needed. Add a few decorative hooks on right side wall for perhaps out of season handbags? Go through what you currently have in there and purge what you don’t use frequently. I would not store pet food in this room at all. Get a desk chair carpet protector to put down on carpet if cat dishes etc remains in this room.

Why are there steps in the closet? What is under them? Is it steps going down to a lower floor and so head room was needed? I think the advice others gave you is good.....to get clear plastic storage boxes to put on the shelves and store things on the top shelf that you do not use often like Christmas Decorations etc. I would keep the floor as clear as possible so you can stand in there and reach the bins.

I agree with others: think of the right side as the normal/active part of the storage and the left/staired part as the "bonus" or long-term storage. Actually, the step doing a good job storing that big blue exercise ball. Maybe have the first step store exercise supplies and the far area be long-term storage or store craft supplies you don't use much, or even things you only need when guests arrive (or leave it open, as a place guests can store their luggage). FWIW, I probably wouldn't put the litter box in the guest room, not only due to the lingering smell, but because the cat dander can build up. What's the dark thing on the wall to the left? Do you need access to that?