Sew4Home shows how to make their Soft and Slouchy Book Bag. If you make it from a sturdy fabric (such as corduroy, as they did in their example), you can avoid using an interfacing that would stiffen the bag. The straps are attached with rivets, and a pair of large pockets on the outside hold smaller items. Get the tutorial.
[photo from Sew4Home]
By Anne Weaver