Garden supplies tend to end up everywhere, especially if you do any potting in your shed. Always make sure to have a clean surface to work on. Old crates work well to hang from your potting area, where you can put small bags of soil, pots and watering cans. For seeds and other loose items, hang a ribbon and attach clothes pin. As you get small packets of seeds, use the clothespins to hang from the ribbon, taking down as needed. This keeps them organized and out of your workspace, so you can make the most of your gardening.
Make sure the entry to the unit is wide enough to accommodate your largest piece of equipment, such as a gas snowblower, with room to spare. Many outdoor storage buildings that are at least 8 feet x 10 feet come with double doors, which usually eliminates this concern.