Read on below for how to make this a two person costume and some other amazing art-themed Halloween ideas.
Using the Munch's the Scream as reference, draw in the basic composition.
paint in the sky
the dark outlines
Carefully cut out the face shape with an x-acto knife. Attach inside frame.
viola---(thanks to dear husband for modeling)
And for a two person costume---I present the Art Heist:
Check out this amazing rendition of Klimt's "the kiss" and a Roy Lichtenstein painting come to life (with tutorial).