Bought some knotted hair ties made from Foldover elastic (FOE) at the beginning of the school year and I never wear a ponytail without one now! They are a fantastic way to dress up a simple hair style. My hair is pretty thick so I usually wear one over a normal hair tie, but for something like the bottom of a braid just the one is enough.
I have these colors, the four on the left are from Forever21 (now sold out) and the six on the right are from Anthropologie. Seems like Emi-Jay is the place to go for the original product.
Found some FOE at Joann Fabrics and bought a few yards for a few dollars per yard. Now that I have done my online research, it seems that FOE generally goes for less so in the future I would go that route.
With my new FOE I made a headband! Super easy, just measured it around my head, added about an inch and a half, cut it, and made a knot with the ends. Super comfortable, cheap, and unique.
Also found this great tutorial to tie dye FOE for an even more unique look, and a great gift!