I like to use it in the shower. Wet your body and/or face with warm water, rub this scrub all over and rinse. For my face, I like to leave it on for a few minutes while I let the antioxidants and caffeine in the coffee absorb into the skin. Then rinse. Follow up with your favorite moisturizer.
Storage: The jar will last for one or two months based on your use. As long as it doesn't get water in it, it should last quite awhile.