This year we decided to go retro and my 12 year old went as a ghost. We looked around on Adafruit and decided we would try and take a part of Phil Burgess’ E-Demon costume and apply it to the ghost’s eyes. At night, the effect worked like a charm. You could just see the outline of this white sheet with big black eyes from the ambient light of the houses and jack o lanterns. Up close the glowing LED eyes really work their charm and turned a lot of heads. In the end, the costume was easy to wear and visibility through the eye holes was still pretty good. We only had to make one stop on our trip to open up the arduino and reconnect some wires that had pulled out of the header.