Use the heaviest duty boxes you can find. Plastic bins would be better than cardboard because they won't wilt in humidity. Stack the boxes neatly with the largest and heaviest on the bottom. Also, label those boxes and make sure the label is facing out. This may seem obvious, but be sure that everyone helping you fill up the unit knows what you expect.
If you are renting a larger storage unit, you might consider investing in some heavy duty shelving units. These can help keep you organized as well as protecting your items.
Even if the storage facility you use has good rodent and bug control, you'll want to take care of this in your own unit. Whether you are storing boxes of household stuff, files or a vehicle, place some rodent bait and/or bug traps in your unit. At Beaver Storage we are happy to provide rodent bait upon request!
If you plan to use your unit later in the evening or early in the mornings or if your unit is particularly deep, you may want to consider some supplemental lighting. A nice option is a battery operated light that has a magnetic back so it can be attached almost anywhere in a unit. These come in LED varieties so batteries will last a long time.
You'll want to make sure that your unit has a lock on it. You want something that acts as a good deterrant and won't rust or fall apart after it's been in the weather for a few months.
Keeping track of the key to your lock could be a challenge. It makes sense if you are going to visit the unit regularly to keep it on your car key ring. Consider attaching a mini flashlight onto the key ring so you won't have to fumble in the dark for your lock. Our facilities have very good night lighting but it's not the same as daylight and a small beam could save you time and hassle.
You might consider a magnetic hide a key box to keep somewhere in your vehicle. Label the storage key with the unit number and you'll always have it handy and available.
Put your contract and other storage paperwork in a folder and keep it with your household or business files. If you forget your gate code or the date your rent is due, you want to have easy access to it. This is also handy if the time ever comes that you want to move out of the unit. You can review the move-out policies to insure that you receive your security deposit refund.
Over time all units tend to collect dust and a little debris. It would be nice if you had a broom handy to give the unit a quick sweep occassionally. At Beaver Storage a broom and dust pan are available for customer use during regular office hours: Tue -Fri. 9am - 1pm and 2pm-5pm and Saturday 9am - 1pm.
Be sure to place a drip pan or absorbent pad under vehicle engines or any piece of equipment that could leak oil or other fluids. An ounce of prevention is really worth a pound of cure in this circumstance. (Just trust me on this one.) If oil or other fluids leak onto the unit floor they will cause a stain and your security deposit will be held to cover cleaning and damage costs.
That should totally trick out your storage unit. Good luck and happy storing!