Using the Topeak EX MTS Trunk Bag is easy. First, attach it to your bike's rear carrier using the integrated straps. Make sure it's securely fastened to avoid any movement while cycling. You can organize your items in the main compartment with the divider and use the mesh side compartments for smaller things. Keep your water bottle in the rear holder for quick access. When not in use, you can carry it by the handle or use the shoulder strap. To maintain it, clean it with a mild soap and water when it gets dirty. Store it in a dry place to prevent damage from moisture. Avoid overloading the bag to keep its shape and functionality.