I do what justflyingin suggested and buy clothes to cut up. I don't buy from GW because they are too expensive so look for other thrift stores if possible. I have a thrift store nearby that has 50% and 75% off items every week so I pay $1 - $2 per item and I know the clothes I buy have been there for 5 or 6 weeks and are heading for the dumpster. A lot of the men's shirts are 100% cotton and I buy women's jumpers for all my denim. I do find handmade dresses a lot for some reason and it goes without saying the larger sizes yield more fabric. I go to another that marks down every week for 3 weeks before the clothes are pulled. Just ask what days they markdown and they will tell you, it is usually Monday and Tuesday. Yard sale clothing is usually pretty cheap too.