Upper cabinets are shallow by design, which means a single shelf wastes the air above it and the strip below it. You can't make them deeper, but you can use the height they do have — twice. The pieces below are sized for shallow uppers, where a full-size organizer would never fit.
Double the shelf with a slide-on
A slide-on under-shelf basket ($27) clips under the existing shelf and becomes a pull-out tier for the light stuff — tea, snack packs, the wraps. Because it pulls out, the shallow depth stops being a reach problem; the basket comes to you.
Fill the strip with a rack
The few inches directly under the shelf fit a under-cabinet rack ($27) built for exactly that strip. Mugs and small bowls live there, freeing the shelf above for plates you use less often. No drill, so it comes down clean if you rearrange.
Lift a hanging tier
If there's clearance under the upper shelf, a hanging shelf organizer ($25) adds a stable second level for cans and boxes. Keep it light so the door still closes, and group by category so the cabinet reads at a glance.
For the deep base below
The base cabinet under the uppers often has a deep floor — a pull-out drawer basket ($30) reaches it so the lower cabinet isn't left out of the plan. Upper tiers plus lower pull-out, all from one wall of cabinet, no remodel.
Use the shallow cabinet fully: see the Cabinet range.