Open the crafting table (2×2 grid).
Place 1 iron ingot in the top-left slot.
Place 1 iron ingot in the top-middle slot.
Place 1 iron ingot in the top-right slot.
Place 1 iron ingot in the middle-left slot.
Place 1 iron ingot in the middle-right slot.
Place 1 iron ingot in the bottom-left slot.
Place 1 iron ingot in the bottom-middle slot.
Place 1 iron ingot in the bottom-right slot.
Place 1 wooden plank in the center slot.
Take the shield from the output slot.