Use thin black or painted black cardboard. Any old red or blue or multi colored bandana will work. Fold it diagonally to form a triangle. Place on your head so the triangle covers the top of your head, and tie in back. Any color, any design.
Pirates often wear one hoop earing.
If the clip on kind hurt your ears, then tie a loop of string through the earring and put it over your ear. Cardboard dagger stuck in your sash. If you are wearing a long-sleeved shirt you can pull the sleeve over your hand and just hold the end of the hook with your hand. If you are holding a hook you need an easily accessible trick or treat bag. Try using a paper bag with a string handle that you can put over your head and one arm.