Step one:
First draw a horizontal line.
Step 2:
Then draw two square door frames.
Step 3:
Draw a diamond shape on the door and a round handle.
Step 4:
Draw a word "福" inside the rhombus.
Step 5:
Then draw a square on the top and bottom of the door, and write your favorite number on the door number.
Step 6:
Finally, paint it with a nice color, and the door is ready.