Chances are good that, in search of a way to untangle your MP3 player earbud cords, you got something like Spacematter's tutorial ( https://www.instructables.com/id/Earbud-cord-wrapper-in-5-minutes-or-less!/ ). While following the instructions, I noticed a flaw: the earbuds were free to unwrap the entire cord if the notches were cut even slightly incorrectly, or you used a card that isn't very flexible, or if you had an MP3 player that wasn't an IPod (incorrect cord diameter).

Step 1: Step 1: Materials for the Cord Wrapper (skip If You Already Have It!)

This is just the cord wrapper tutorial from Spacematters, rehashed.

MATERIALS:
-Altoids tin or equivalent.
-Credit/debit/etc. card
-The earbuds you want to store
-A paper clip
-Scissors to cut the credit card
-Tape and/or super glue
-(optional) Hole punch
-A BRAIN!

Step 2: Step 2: Making the Cord Wrapper (skip If You Already Have It)

This is the hard part, the actual cord wrapper. Make sure to test it between cuts!
1. Cut the cord into 3 parts.
2. Make holes and slots for the cord, as seen in Spacematter's tutorial (as well as mine)
3. Fine-tune the slots (cut them until they work!)

Step 3: Step 3: Improving the Cord Wrapper (DO NOT SKIP)

Well, the hard part's over, now you just need to improve it!

1. Get a paper clip, and bend it as shown in the first picture.
2. Tape/glue the paper clip as shown in the fourth picture.
3. Get your Altoids tin. If it fits, you've finished the improvements.

Step 4: How-to-use Your Improved Earbud Cord Wrapper!

If you're in the mood for some confusion, skip this step. If not, then read on.

1. Get your cord wrapper, Altoids tin, and earbuds.
2. Wrap the cord around the cord wrapper until there's less than an inch of loose cord on the earbud side.
3. See picture 2.
3a. Fit the cord through the crevice between the 90-degree bend in the paper clip at Point 1.
3b. Pull the cord past Point 2 in the direction of point 3. Expect some friction.
3c. Keep pulling until nothing is clipping/grabbing onto the earbud cord. However, if you find doing steps 3a-3c in reverse difficult, ignore this step.
4. Your earbuds SHOULD dangle freely, but unless you do steps 3a-3c in reverse, they should not unwind the cord from the wrapper.
5. Fit the improved wrapper and the wrapped cord into an Altoids tin, so as to protect the wrapper and keep the cord from being damaged.