I once invested in a Kickstarter for a leather headphone strap with magnets inside. Sadly after 4+ years I lost it, and I wondered if I could resew it. While playing around with rare earth magnets, I realized I could use vinyl tape and dimes to quick rig a similar kind of thing.
Vinyl electric tape (or fabric tape)
Two 10mm rare earth magnet discs
Step 1: Measure Tape
Roll out a length of tape, putting 3 dimes close to each other, then a slight space, then two more, closely placed.
Step 2: Magnets
Move dime 1 next to dime 5, and put the two magnets there. Then, flip the top magnet, so it will easily reconnect to the bottom one, and replace the last dime with it.
Step 3: Cover and Cut.
Roll out enough tape to cover everything, then cut!
Step 4: Decorate and Enjoy!
Just fold it in half over any cable to use.
I covered mine with fabric tape, it feels nicer this way. Hopefully this will do the job till I can make a leather version!