Utilized Pegboards - Pegboards are a great tool that can be used almost anywhere in the home for organization. The same is true for your shed. For small tools, such as hand shovels and rakes, attach a pegboard to a wall and use various hooks and hangers to place hand tools and other items on. This gets them off the ground, out of the way and in a consistent spot that is easy to find.
Buying an outdoor storage building with a loft greatly increases storage capability, allowing you to store rarely used supplies overhead. For the exterior, build your own lean-to and attach it to the outdoor storage building to form a sheltered area for firewood.