styrofoam covered with fabric wall art. My daughter and I did this for her room. We used cheap painter canvas and scrapbook paper. We sprayed adhesive glue to the canvas and layed the scrapbook paper on top.
Glue crayons to a piece of cardboard or to the a canvas. Then get a blow dryer, turn it on, and hold at an angle. The crayon will start to melt and drip in the direction of the hot air. Put cardboard behind the art piece, the crayon will splatter.