Instructions
Place six wood planks or iron ingots into a crafting table, and arrange them into two adjacent columns of three items each to create a door.
Place two wood planks or stone blocks into a crafting table, and arrange them so they are side by side horizontally to create a pressure plate. Repeat this process to create a second pressure plate.
Place the door in the desired location.
Place a pressure plate on the block directly in front of the door. Walking over this pressure plate will cause the door to open automatically.
Place the second pressure plate on the other side of the door to allow the door to open automatically from both sides.