Separate the items in your garage according to category. Groups could include tools, sports equipment, cleaning supplies and trash.
Throw all the trash away. Donate items to friends or charities if they still are good but you won't use them anymore.
Designate areas of the garage for different categories. Tools belong in one area, trash and recycling in another, sports equipment in another. Put the most-used items in places that are easily accessible.
Install hooks, shelves, cabinets and cubbyholes to store garage items. Set up subcategories in each location and store like items with like: all hockey sticks in one location, for instance. Label the shelves to make locating items easier.