A foldable carrying case is described that has an integrated one-piece body of hingeably connected panels, and flexible gussets hingeably connected to the panels. The body is further provided with releasable fasteners. The body converts from a plane configuration to a container configuration, and vice versa. The container configuration is formed by folding the panels and the gussets, and the panels and gussets are connected by the releasable fasteners to prevent the container from unfolding. Also described is a method for making and using such a foldable carrying case. Also described is a kit including such a foldable carrying case and at least one storage container.