Pull-out drawers and shelves allow access to items stored in the back of a deep cabinet. Add storage on the inside of the cabinet door, too.
In pantry cabinets, use handled bins to store items often used together (like oil and vinegar). This makes it easy to retrieve them from a deep shelf.
Under the sink, long stackable storage bins help maximize usable space. Store less-used items in the bottom bins. And label everything!
Maximize vertical space in a deep cabinet with cup hangers. This can double the available storage space and make it easier to access your cups.