Place the cutting board on a sturdy surface.
Place the artwork on the cutting board. Then place the tracing paper on top of the artwork.
Secure all edges with masking tape. Trace the design and all of its details with a soft pencil.
Flip over the tracing paper and tape it to the poster board, leaving room around the edges. Trace over the pencil lines onto the poster board.
Lift the imprint slowly to see if your pencil lines are distinct enough to see and cut. If not, return the tracing paper to the board and retrace the imprint. If so, use a sharpened craft knife to score the lines to create the stencil. Slowly cut through the lines with the craft knife, taking corners cautiously. Rotate the cutting board rather than attempting to make awkward cutting maneuvers with your hand.