I grow my gardens the way I arrange bouquets, with focal plants and filler plants.
First the vase (the bones of the garden), then the filler (the repetitive plantings), and then the focal points.
In this bouquet, I have a simple but elegant silver vase with white fuzzy salvia, hyacinth beans, purple basil, perennial asters, and almost black Dahlias.
I grow Salvias and purple basils along the borders in my garden, white and purple Hyacinth Bean vines are my height plants, and Dahlias and Asters serve as my focal point plants. They all come together in the vase as well as in the garden.
As I was planning this garden, I thought of design schemes I'd like to see as an admirer of colors and contrasts, and then I ordered the plants and implemented them in the design of the garden.
If plants don't do well, I can always change them out.
Where I live, there are many wholesale growers, so it's an inexpensive proposition.