Heat from the sun
Draw an outline of a flower or what ever you want on a piece of construction paper. Place the crayon shavings within the lines of the flower shape to make a colorful design. Carefully place the picture outside in the sun. Place a rock or some other heavy object, on the paper to keep it still. Allow the shavings to melt. For best results, leave the paper outside overnight to allow the shavings to harden completely.