I'm enough of an experienced gardener to know that many of the perennial borders that I admire on garden visits require lots of maintenance and change-out of plants.
They're beautiful, certainly, but folks like me that don't have full-time to devote to their gardens (uh, isn't that most of us?) would rather have lower maintenance mixed shrub and herbaceous perennials in focused areas, with naturalistic plantings elsewhere, with 'color' in specific spots in our garden, often in containers.
At least, that's my approach!
I like to use foliage colors and textures to provide a soothing feel, in addition to the blues, grays, yellows, and purples that stem from flowers and leaves.
The shed border, undergoing a pleasant transition, is anchored by a large rosemary, but surrounded with Coreopsis 'Nana', ornamental alliums, and Agastache growing rapidly at this point in the year. Earlier in spring, Veronica umbrosa 'Georgia Blue' added color to this border. I lost a lovely Rosemary 'Irene' on the far left of the border last year, probably due to our exceptionally cold winter. But the Agastache and Phlox have quickly established their new spaces in the bed.