http://www.dailymail.co.uk/sciencetech/article-2683086/How-make-sure-earphones-NEVER-tangled-Mystery-spontaneous-knots-solved-thanks-string-theory.html
It works. I made a clip out of an old credit card (it’s sort of like a bread bag clip), and I carry my earbuds in my jacket or backpack for months at a time, because they’re for emergency use only. No tangles. I’m sure there are ones you can buy that would be more convenient for frequent use.