This woman's tutorial/walk-through on how she made her costume wings is *amazing*. Awesome creativity, and some pretty amazing engineering! Perfect for cosplay (I absolutely have to make a set of these wings)
Cardoard cutouts painted black with the eyes cut out and a glow stick in a little box glued (or duct taped) to the back of the head.if you don't want to do full sized cutouts, you could just do creepy figures in windows.
Costume - Doll up for Halloween this year with a simple DIY add on to a cute baby doll dress and voila! This wind-up key is so easy to make! All you need is some cardboard, paper towel tube and metallic paint. Makes great last-minute costumes!