There are quite a number of ways to grow flowers in the garden. Color can unify a garden, with hints of color, monochromatic themes, etc. Flowers can also be grouped based on texture, height, blooming time, and other characteristics. Thinking about bloom time is important to ensure that there are interesting things happening in the garden all year. In colder areas where it snows, there are less seasons to think about.
When planting flowers, it is important to think about soil. Whether you have clay, sand, or loam soil it will be important to ensure the soil is amended as necessary to ensure water retention, aeration, and drainage. Adding compost and other good quality organic matter will ensure plants have nutrients over time.