Angle. Think about how the bed looks from different parts of the garden ― from paths, patios, or other gathering places, or from living room windows. Angle the bed for best viewing from one or more of those locations.
Shape. A bed in the shape of a circle, square, or octagon looks formal, while one with a free-form shape has a casual look. Experiment by laying a hose on the ground and adjusting its curves.
Height. To add visual interest to a level bed, mound soil in the center or at one end to create a gentle berm ― an elevated stage for an art object or accent plant.
Edging. Want it to look crisp? Outline it with bricks or slate pavers. Want it soft and informal? Plant billowing perennials instead, such as dwarf lavenders.
Accents. A shapely boulder, a single, well-placed piece of garden art, or a low-growing Japanese maple makes the perfect finishing touch when it rises above lower plantings.
Color and texture. For the "bones" of your beds, choose permanent plants with interesting foliage.