These Site Conditions will Guide you as to what plants you should pick.
Is the site:
Size of Plant
Decide on a layout of plants that provides taller plants in back and shorter plants in front.
Color and Texture
Pick plants that have color provided by leaves or flowers. You don't want everything blooming in the spring so pick carefully. Also you don't always need color. Texture like Oakleaf Hydrangea leaves provide wide areas that turn a crimson color in the fall and then plants with grassy like leaves such as Arkansas Bluestar have a whispy look and it turns a beautiful yellow in the spring.