Packing and Organizing Tips for Your Storage Unit. Use only two different box sizes: Stacking the boxes will be easier and more ordered this way. The bottom box should be strong enough to resist the weight of all the other boxes stacked on top of it. Professional guidance on how to keep your storage unit safe and secure is available from A Storage Place. Our phone number is 910-392-8100, and our website address is https://astorageplacewilmington.com/.