I have made several rag throws for my grandkids. They love them. I use old flannel shirts & old jeans. Cut these into 6 or 8 inch suares or whatever you want. I sandwich these with flannel sheet squares, cut slightly smaller. Jeans on one side, flannel on the other. Sew an X through each one. Sew them together with one inch seams. Cut each side of squares about 1/4 inch apart, so that they will fray. Toss in the washer & dryer. Be sure to check the dryer screen several times during drying. The screen will fill up with lint. Also, you have to really clean lint from your washer. You can use quilting material instead of flannel shirts if you want. I bought 18 pairs of jeans for 3$ at our local thrift store.
Making them is more labor intensive than expensive, which is great for me since I have 7 grandkids and 6 great-grandkids. Being retired I have more time than money.