One idea is to dress in all black clothes. You may have some black clothes around the house or they can be purchased at a thrift shop or you can dye some old cloths black. You can wear the dress very long or short with tights as above.

You can also make your costume like the one in the photo with some orange satin. Purple also looks well. A tall hat can be fabricated from black construction paper or you can buy one fairly cheaply at a costume store.

Of course we know that witches were neither green skinned nor ugly. They were simply ordinary people. However if you like to pretend you can use the recipe for makeup on the main costume page and apply green makeup. If you have a fake kitten you might want to carry it around or bring a short broom that wont get caught in your clothing.