Categorize garage contents. Many garages tend to be a dumping zone for everything that doesn't have a designated spot to reside in your house. Once you have established the categories of items that actually belong in the garage, pull everything out and group them in the driveway or the center of the garage. When necessary box items, either for storage or just for sorting. Items that will remain in boxes for storage should be marked right away as to their contents.
Once you have categorized and consolidated all items in your garage, get rid of any excess. Determine where you want each item to reside by frequency of use and available space. Recycling should be near the entrance for ease of use, tools should go close to workbenches and so on.