Once I had examined the pattern of the lace, I got to work with a needle and thread.
With one edge that had cascading larger holes, I strung a bunch of beads on some tatting thread and crocheted them onto the edge.
The back is comfy, though I suppose I could fix a piece of cloth to it if I get ambitious.
The fastener was the most difficult part. I had some neodymium magnets, which are super strong. I made two small envelopes and slipped two magnets into each of them. Then I sewed them onto the ends, and just folded up/cleaned up the frayed edges of the lace. This made the fastener magnetic, so I don't have to have any one else help me put it on, but also secure without pulling on the edges of the lace and eventually coming undone. The cloth does cut down on the strength of the magnet, but it's fairly loose, so I don't have to worry about accidentally popping it open if I move my wrist.
All in all, a very fun little project.