When you don't have a lot of storage space, your best bet is to build up. You can purchase steel and plastic shelves from your home improvement store, but the steel shelves are expensive and heavy, and the plastic shelves can sag and fall apart. Take some time to build your own shelves from wood, and you'll have a fully customisable and solid storage solution.
Your local hardware store or timber yard has everything you need to build your own storage shelves. Heck, you may even have enough materials in your scrap timber pile to build a storage rack.
All you need are a few 2x4s, OSB (or plywood), and 5cm deck screws. This particular shelving unit has four levels and is supported by six 2x4s. A drill/driver, level and measuring tape are required to assemble the unit. This video shows the use of tote boxes and a 2x4 to help hold each new shelf in place as it's being attached.
Watch the video above for the full cut list and assembly instructions.
How to Build Cheap Shelves Garage Storage [FloppyHatPhotos/YouTube]