I just happened across a free PDF of this fab 1920s booklet on sewing with cotton bags and thought you might like it too. Produced by the Beauty Pattern Company, which presumably made mail order patterns, it’s full of suggested patterns and inspiration for sewing with feedsacks.
EDITED TO ADD: the person who scanned the original booklet dates this to the 1920s, but we think it looks more like 1930s style and hugely smart reader Bry found one of the patterns in this 1935 publication
P.S. If you love things like this (who here doesn’t?), consider following WeSewRetro on facebook as that’s where I usually put all the fabulous links