Using this Raskullz Skull Hawk helmet is easy. First, adjust the nylon straps so that the helmet fits snugly on your child's head, with the size ranging from 50 - 54 cm. Make sure it's not too tight or too loose. When your child is riding, ensure the helmet is worn properly at all times. As for maintenance, you can use a soft, damp cloth to wipe the outside of the helmet clean. Avoid using harsh chemicals as they might damage the matte/gloss finish. Check the inner shell and straps regularly for any signs of wear and tear. If you notice any issues, it might be time to replace the helmet. Also, keep in mind that this helmet is designed for children aged 5 to 8 years, so don't let older or younger kids use it for safety reasons.