How can I build a sturdy 2x4 garage shelf to maximize storage space?

To build a sturdy 2x4 garage shelf for maximum storage space, start by measuring the area where the shelf will go. Cut the 2x4s to the desired length for the shelf and support beams. Use screws and brackets to secure the pieces together, ensuring they are level and stable. Add additional support beams for strength and consider adding shelves at different heights for more storage options. Finally, secure the shelf to the wall for added stability.