How can I effectively position plants in my garden to create a visually appealing and harmonious layout?

To create a visually appealing and harmonious garden layout, consider the height, color, texture, and spacing of plants. Place taller plants at the back and shorter ones in the front for depth. Use a variety of colors and textures to add interest. Group plants with similar water and sunlight needs together. Balance the layout by evenly spacing plants and creating focal points.