Storage containers have a wide top and a narrow bottom. When placed side by side there is a small space. I use that space to store a box of sandwich bags and a flashlight; easy access for two frequently used items.
In the inside, upper part of a cabinet extra aerosol cans are stored on a shelf I fastened in there.
In the top, back of my closet, I installed a narrow shelf for gloves and hats; this one turned out exceptionally well.
I have one, 9 foot long shelf that I keep my 7 foot long straight edge. Finding a safe place for that was difficult.
When people have two wheel drives they often have more of a need for winches and other extrication equipment that takes up precious space in their rigs. My truck is four wheel drive with my extrication equipment "stored" in the form of a transfer case and a front axle with a differential. Not unique, but a unique way of looking at storage.
My Sam's Club cabinets were too low for comfort so I built a platform to raise them so the counter level was at an appropriate level. Underneath I store heavier items.
My ladder is stored against a wall with bungi straps. Not storage per se, but an effective way to keep an item out of the way while still having easy access. Looks good, too. Storage doesn't have to be in a box or covered up somehow. Another way to look at storage differently.
Finally, do you remember those old Sampsonite toiletry cases? The hard sided ones? You don't see those around so much anymore. Instead of installing a medicine cabinet on the wall, I use that instead. Works awesome. I saw a guy on the Internet glue a mirror on a Pelican box on the wall and use it as a real medicine cabinet. He put a spacer on the bottom of the cabinet so it tilted back to help prevent items from falling out. That idea impressed me.
