As a bonus, these light up Christmas tree costumes have the built-in nighttime safety feature of actually lighting up! So trick-or-treating can go extra late this year.
Step 1: Create Base
I cut two full dresses for both costumes. Since there were to be a whole mess of wires winding about inside of the costumes, I wanted an extra layer to protect the girls from the wires and the wires from the girls.
Next I sewed together the inner dresses, leaving one shoulder open so they could get them over their heads.
For the outer dresses that would need to be wired, I sewed together one side seam only.