Think about location. Are you going to need to access your storage building frequently? If so, aim for someplace nearby.
Consider how much space you really need. Self-storage facilities rent units in all different sizes. It's best to opt for a smaller storage unit and pack it to the ceiling rather than pay for space you're not using. If even the smallest storage units are too much, look into mini-storage facilities: self-storage facilities that specialize in small loads.
Be sure to ask facility representatives how and when you can access your unit. Most self-storage and mini-storage facilities allow for free access 24 hours a day, but some facilities have restrictions and others charge fees for access.
Also ask about climate controlled units. If you're storing anything valuable or delicate - like antique furniture or important documents - it could be warped by being stored in space that's too hot, too cold or too humid. For an extra cost, most public storage facilities can set you up with a unit where temperature and humidity are restricted.
Try to use boxes that are a uniform size, they're easier to stack (remember; keep the heavy ones on the bottom and the light ones on top).
Leave small walkways between the boxes and furniture in your storage unit so you can easily get to the items you want without having to move anything around.
If you're storing a lot of packing boxes in your unit, try to fill them to the top, even if it's just with padding and old, crumpled newspapers. Boxes that are only half-filled tend to collapse if anything's placed on them.
If you're putting any metal objects into storage - like lawnmowers or file cabinets - it's best to treat them with rust protector first, or at least wipe them down with an oily rag.
Most public storage facilities have ample security. However, it's still wise to take a few precautions of your own against theft. Pack your storage unit so that your most valuable items are at the back, and purchase a high quality padlock to put on the door.
The humidity in your self-storage unit can cause your furniture to warp and your appliances to mildew. Leaving a space between your stuff and the unit's wall allows for air to circulate within the unit. Laying plastic sheeting on the floor and stacking boxes on top of wooden pallets can prevent condensation damage. So can using old linens or other fabrics, instead of plastic, to protect your stuff from dust.
If you're storing a refrigerator in your unit leave the door ajar. This will prevent mold from growing inside.
Under no circumstances should you keep anything flammable or combustible in your storage building. This means no fuel, oil, cleaning fluids or paint thinner. If you're storing any machinery that runs on fuel, drain the tank before you store it.