When designing any plant bed, there are 3 main plants you'll want to focus on. Specimen plants (usually an ornamental tree), accent plants (roses or other shrub to provide color), and a key plant (larger tree/shrub to help house feel the right size).
If you've ever wondered which flowers work best in your yard, this is the site for you! Burpee's "My Garden Designer". It's a mobile design tool made to take the guesswork out of flower color, height and compatibility. Even will create a shopping list for you!