Using this cat poncho costume is super easy. Just put the poncho over your cat's body through the cut - out sleeves. Then, gently place the cat ear headband on your cat's head. When it comes to sizing, always refer to the size guide to ensure a proper fit for your furry friend. As for maintenance, hand wash the costume. This will help keep the colors bright and the fabric in good condition. Avoid machine washing as it may damage the delicate details of the poncho and headband. Also, be gentle when dressing your cat to make sure they are comfortable wearing the costume.