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.
If you want to go a step further and separate your tools, you'll need to get a bit more creative. One way is to utilize PVC pipe to make containers for your tools by attaching to two pieces of wood and hanging that from the wall. Another solution is to utilize a pegboard for your larger items as well, as they can hang from hooks similarly to smaller items.