I am in the process of making potato bags for my co-workers. They are VERY fast, but they do take more than a little fabric. Also you have to be sure you use only 100% cotton in your fabric, thread and batting. Here is the link to the ones I am doing; the only thing I changed is I am cutting them 12.5 x 22 instead of 10 x 22.
http://web.archive.org/web/200712021...otato_bags.htm
Also these coasters can be increased in size to 8 x 8 to make hot pads.
http://allsorts.typepad.com/allsorts/2006/11/crisscross_coas.html
Darren