If you have a pattern, and basic sewing skills, you can make cloth diapers from a variety of fabrics, including old cotton t-shirts. You can put cute flannel fabric on the "outside" if you want to, but a little elastic enclosed in the leg sides is a popular pattern. It does not cost much to make your own diapers, especially if you use sheets & t-shirts from freecycle or thrift stores.
There is a link under 'Heirloom Sewing" with several free cloth diaper patterns on theprudenthomemaker.com site, as well as some sewing advice on making your own.