Drawing a Door and Lintel

This isn't a hard symbol at all. It's just a few rectangles with some splotches on them. Here's all you need to do to make this design:
Start out by drawing a simple square. Extend the bottom line a little distance on both sides so it looks like the square is resting on the ground.
Draw lines between the corners of the square.
Place a mark on one of these new lines to mark one of the upper corners of another square. Once you've done that, extend lines from the mark horizontally and downwards.
To add the last line, start from the spot where the horizontal line drawn in the last step connects with the second diagonal line and draw downwards.
Add some smears on the three rectangles.
And now the door and lintel has been completed!