When it comes to knocking up something like a scalloped border, I like to keep things quick and easy. Illustrator is the perfect tool for creating useful little vectors like the one above. They can be welded to other elements and saved as SVGs to be cut with cutting machines like the Silhouette, for example.
I have written up a free tutorial, PDF format, and if you would like to create your own and follow my ten-step programme, download it here:
Hope you find it useful.