At least half of my stash is from deconstructed clothing, sheets, curtains, and bed skirts. I look for 100% cotton but if the feel is really good, I might let in something with 25-30% poly. One of my favorite to use is nurses' scrubs as they usually are very good quality fabric and have lots of variety in the prints. I shop our 4 local thrift shops and generally only buy things that are on the 50% off color tags.