Store polyester sewing thread in a cool, dry place away from direct sunlight to prevent fading and degradation. Keeping it in a thread organizer or box can help prevent tangling and dust accumulation. Additionally, avoid exposure to chemicals, such as cleaning agents or perfumes, which can cause the fibers to deteriorate. Periodically inspect the polyester sewing thread for any signs of damage or weakening. Labeling different colors and types of polyester sewing thread can also save time and reduce the risk of using the wrong polyester cone thread for a project.