To use this Harry Potter glass gift set, simply fill the mug with your favorite hot or cold beverage. The coasters are there to protect your surfaces from spills and heat marks. When it comes to cleaning, hand wash the mug and coasters with mild soap and warm water. Avoid using abrasive cleaners or scrubbers as they may damage the printed designs. Keep the set in a dry place to maintain its quality. Enjoy sipping your drinks while showing off your love for the Harry Potter world!