Step 7: Buttresses
If you want to avoid the need for buttresses, you can make your wall curvy, which is much stronger than a straight wall. You can also make the wall shorter. To do this, you should build into a hill. Start off with a short wall on the ground, a few feet tall, and back fill with dirt. Then you start another wall a couple of feet back, and up the hill a little. This will give you a natural shelf inside the house.