In addition to plants, a garden needs a feature to elevate its importance visually. Design elements of water, seating, and structures can help, but when a garden is void of all of these, you need to be more inventive.
In a modern design, the feature can be sculptural; if traditional, statuary is often appropriate. However, sentiment, cost, and convenience may bend your taste toward a pot or a collection of pots, a planted container, some boulders, a decorative wall plaque , a niche, or a mere glimpse of something such as a window frame. Whatever the choice, it should both catch the eye and give structure and purpose to the garden or its plantings