To use your Harry Potter mug and coaster set, simply place the coaster on a flat surface and put your hot or cold beverage in the mug. It's great for any kind of drink, like coffee, tea, or hot chocolate. When it comes to cleaning, hand - wash the mug and coaster with mild dish soap and warm water. Avoid using abrasive cleaners as they may damage the ceramic or the cork. Store the set in a cool, dry place, preferably inside the gift tin when not in use. This will keep the set looking great and ready for your next magical sip.