This turned out to be a good thing, because it let us figure out some things we knew we wanted, like adding in space for muddy boots, snow pants, etc. It also let me realize that it was inconvenient as hell to have the garden supplies to the side of the door I couldn't just reach from inside the house.
So the second phase resulted in me heading to The Container Store to make several modifications to the original plan. The section we were primarily concerned with is this one:
Order placed and shelves acquired, I took them back home. Once C and G woke up from their naps, it took me about an hour to have everything done.
After the shelves were up, I made a sketch of the full wall and started categorizing where things would go.
Looking at the back wall of the garage now, the small shelf becomes "bagged goods". A basket was relocated to store dirty rags and the like.