I've made grocery bags from farm feed bags for my daughter & she loves them. A lot of feed/bird seed come in bags that are made with woven polypropylene. Here's a tutorial on how to make them.
http://fresheggsdaily.com/2012/01/ma...-bag-tote.html
There are other tutorials online but I like this one. Some use a portion of the bag to make the handles but I prefer to use webbing for the handles. I get these bags all the time with my feed.