Die cutting machines, decorative edge scissors and punches can make some amazing borders.
But, don't discount stickers and die cuts. They can make unique borders on cards, too.
Just look at this one Candy created ...
Next, she took a die cut from Creative Imaginations, inked the edges, and used dimensional foam to adhere it.
Then, she ran flower die cuts (from the same package by Creative Imaginations) ran them through the Xyron Sticker Maker to turn them into little stickers and then adhered them to the bottom and right corner of the card.
Using detail scissors, she cut the cardstock and paper away from the areas below the flowers.
Finally, she added a touch of Distress Ink to the bottom edge to finish it off.
Simple and unique.