cut up shirts; But instead of tying, I'd just cut it short so it's a half shirt. Good idea for those hot summer days when you need the thin tank top but the covered upper abdomen.
"This becomes an upcycle project when you use threadbare sheets, old shirts, or towels which aren’t terribly useful as towels anymore. =^.^= If you go with the towels, cut the strips a bit more narrow to make assembly easier. If the strips are less than an inch across and still too snug to push through with no tools, break out a crochet hook! (Or even a bobby pin)"