For a border over two rows, a great solution is Tramme. It's a unique and attractive border solution that breaks outside of the traditional extended cashmere stitch or padding. The overarching concept is discussed here and here.
I like it for a border because it is understated and can be subtle. The first diagram demonstrates that point.
For the base rows (the gray lines), I encourage you to use a wide and dramatic thread like velvet or an oversized pearl. For a border stitch, both the base thread and the accent threads (yellow lines) contribute significantly to the overall look, more so than the typical tramme stitch (in my opinion).
The second variation of this theme adds a contrasting accent.
The sequence is to add the base rows (gray lines), followed by first set of accent threads (numbered lines), and end with the last set of accent threads (lettered lines). The contrast can be with color (as diagrammed) or with thread finish in the same color values.
The last variation is to add an X over the base threads.
These stitch diagrams, along with other #whimsicalwednesday and #smallspacesunday stitch diagrams, can also be found on www.pinterest.com/whimsicalstitch/whimsicalwednesday.
If you like what you see on this blog, want to learn some very creative decorative stitches, and how to put them all together, whimsicalstitch.com sells stitch guides for seasonal Melissa Shirley designs. 20 guides are currently available and more are in the pipeline.