The designer has employed the concept of asymmetrical balance; one garden bed is larger than the other but is weighted to look equal. The stone pillar mimics the lamppost, bringing continuity to the space. Notice how the caladiums (Caladium sp, zones 9 to 10) are more prominent in the smaller bed on the right. Acting as a fulcrum, they balance the beds, making them visually pleasing. A carpet of ground cover in the foreground of each bed brings that additional dose of soothing continuity.
If you are not confident in your ability to lay out bed lines that seem to flow effortlessly across your hardscape, consider employing the use of a garden hose. Stretch it across your walkway and create a serpentine or curved line that makes sense to you when viewed from different angles. It's easier to change the hose than to redig your bed lines.
More gorgeous looks for a narrow planting strip
The restrained use of boulders can be an effective tool in achieving continuity from one side of the hardscape to the other. Just be sure not to overdo it.
Notice the repetition achieved in this garden through the use of ornamental grasses, hydrangeas and spreading perennials. Some maintenance and planning are required to assure that the plants never present a hazard to the visitor or look overgrown.
More plants for your pathways