Clean out the storage place by removing everything and cleaning it. Do this as thoroughly as possible in case you don't have a chance to do it again for a while. Throw out anything you don't need or organize a garage sale.
Look at what you're working with. After the storage place is completely empty and clean, you have to assess how much room there is and what kind of storage components you will need. If the walls are high, you will benefit from cupboards and closets. If they are low, plastic boxes can suffice. If you're buying furniture closet space, make measurements before you buy anything.
Begin with the items you don't frequently use, such as seasonal things and memorabilia. Organize them and put them in clear plastic labeled boxes. Put the boxes on overhead compartments or pile them up in a corner.
Make use of wall space. Hang things such as skis, bicycles, tools or watering hoses. If you don't have anything to hang them on, buy hooks or install a shelving system.