Place the tallest flower types in the back of the bed if you can view the garden from only one general direction. If the bed is viewable from multiple directions, place the tallest plants in the center of the garden area. The heights of the flowers should become progressively lower toward the front of the bed.
Group flowers with similar heights by alternating textures to increase the visual interest of the garden. For example, place a group of compact flowers next to a variety that has a spreading train.
Plant a mixture of flower colors in the beds, using the bold colors of orange, red and yellow to pop from a distance and white, silver or gray between them to blend the colors from one side of the bed to the other. Purple, blue and green flowers show up best in beds that are close to their viewers, such as locations near porches, patios and sunrooms.
Place flowers in masses of three to six plants unless they grow as large, spreading shrubs such as peonies. Plant the flowers in arcs rather than straight rows unless the garden is formal. For large beds, repeat masses of the same flowers throughout the bed.