Lay the poster sheet flat in the centre of the table before children finish their individual crafts. Write the year in large block letters across the top with the thick black marker, leaving the rest of the sheet open. This takes about one minute and anchors the composition before anything is glued.

Each child selects one piece or offcut from their own craft: a ghost handprint, a test bat, a scrap of gauze from the mummy, a spare skull shape. They decide where on the poster it should go, apply glue to the back, and press it down. Let everyone add their contribution before anyone moves anything.

Fill any large empty gaps with extra offcuts, turning scraps sideways or overlapping pieces until the sheet looks full rather than sparse. Press the whole poster flat under heavy books for ten minutes. Display pinned to a wall or roll it and store in a cardboard tube. It will look better every year you bring it back out.