Determine what kinds of containers will best store these items. Bicycles can be hung from the rafters when not in use. When the bicycles are in use, assign a certain place for them to be parked. Keep as many items off the floor as possible so it's easy to sweep often. If you have bare studs in the garage, place slats of wood across the studs to create bins for items like sports equipment and gardening tools.
Hammer nails into the wall or into the studs for tools and other articles.
Keep similar items together in marked containers and go through them once a season to clean out things you're not using anymore. Hang shelves and keep storage containers marked with items like toys, tennis balls, nails, lawn chemicals, etc. Use hooks instead of nails for items such as outdoor clothing, backpacks, umbrellas, etc. Strap items like bats and fishing rod together for easier storage and transport. Take this organizing opportunity to make inventory of items you'll need for the spring such as missing garden tools.