Decorating an enclosure is more for you, however some things I know some balls in the past took an interest in:
Sticks, fat, skinny at the top, secure ones that won't fall if they climb onto them
Logs for hiding and rubbing (not to be used as their main hides)
Moss
Plants, leafy coverage
They are really curious snakes tbh, anything you put in there they will check out and try to get into it, juts be sure it;s safe for them.