I looked around at other sleeves and they seemed to be mostly made out of Neoprene and looked simple to make. I decided to make one myself.
Step 1: Items Needed
A piece of Headliner or similar fabric large enough to cover device
A piece of Elastic roughly half the height of the device
Electronic Device to protect
Step 2: Measuring
My MP3 player was exactly 10cmx5cmx1cm so I decided just to do everything in Centimeters and have nice even numbers.
The fabric I needed to cut needs to be 23cmx7cm to allow space for the foam fabric and the stitches.
Using a state of the art marking implement called a ultra fine point sharpie I marked it out and cut it out very nicely.
I decided to make mine a little longer in the next step you'll see why.
Step 3: First Stitches
Pin it together first so its easier to sew and I doubled up my tread so its stronger.
Do this to both ends.
I have no idea what this type of stitch is called I'm sure one of you guys will know and tell me and I'll change this but its sort of a knot after each stitch I just figured it out myself; look at the picture to see if it help.
Step 4: Adding Headphone Holder
Sew the ends of the elastic together like the other piece of Fabric.
I messed up the first time and the elastic was too long so I had to cut an end off and redo it.
Now sew each ends of the headphone jig to outside of the devices sleeve like in the picture, you may not want to do this until you make your first sleeve, this way if you don't like how it looks you can make a new improved sleeve without having to get more elastic. I did this myself while making this instructable because I could already see somethings needed changing.
Step 5: Final Stitches
Now turn it right side out so the nice black is showing and give it a test ride.
The last thing to do is look at all its flaws. Mine is too short and tight making it difficult to insert the P2 and it sticks out a little too much. Now since I didn't sew my elastic on the first time I am able to save it for a new better case which I'll build in a few minuets and you'll see it on the next step.
I'd like to say that this surely was much cheaper then buying a case from the store it may not look as nice but its definitely protective. In total I spent $1.75 on the fabric with tax and $.05 on the elastic, I already had the other item so I spent a total of a $1.80. That means I saved over $30 dollars not buying a case form the store.