Using these packing cubes is a breeze. First, sort your clothes or other items by type and size, then place them in the appropriate cube - the medium one for smaller things and the large one for bulkier items. When packing your Travel Cloud Bag or Cloud Carry On, just slide the cubes in. To keep them in good shape, machine wash them when they get dirty, but avoid using harsh detergents. Store them in a dry place when not in use to prevent any mold or mildew.