Sometimes the best thing for a yard is a wooden retaining wall. Although more subtle than brickwork, it can also really fit in with a more rustic yard. While understated, a retaining wall can help terrace a yard for plants, or provide a nice break between different elevations.
A simple retaining wall, or set of walls is great, but what about a retaining wall that also encloses a planter? Perfect for growing vegetables, or getting started with flowers, it can also be the perfect thing for an empty yard.