My fancypants Sony headphones, (which went missing and actually prompted me to create the aforementioned thingy) were showing some wear and tear: the foam covers over the speakers were deteriorating. I see people on the bus with this ailment frequently. Doesn't affect the device much at first, but all manner of scuz gets in there overtime, and that can't benefit the sound quality.
Anyway, the fixit occurred to me a couple days ago, and in that span of time the good digital camera went to Germany with the fatherly unit. Consequently, I apologize for the poor quality images via cellphone with bad lighting.
Step 1: Materials
-headphones with degrading/dead foam covers
-fabric (old pjs worked well, but anything thin, with a loose weave and minimal fuzz would do) [bright colors optional]
-scissors (if you are going to use 3rd grader scissors like I did, give them a good sharpening first)
Step 2: Sewing a pattern
If you really are adverse to sewing, you could even subsitute superglue, or get creative with rubber bands or something... let your laziness flow.
First you remove the old, earwaxy foam covers from your headphones.
Cut two squares of fabric about an inch bigger than the diameter of those foam covers.
Step 3: The tricky-ish part
Note: sewing a perfect circle is not important!