Here is one I use. It's super easy. It's fully lined too! and you can piece the fabric or embellish it, add pockets, or make it plain. Make it any size. It's so easy kids can make them. My grandmother use to make these from pillowcases but they weren't called tote bags then. LOL Here is an online tutorial of an updated pattern:
http://www.lazygirldesigns.com/blog/...iday-gift-bags
For a more firm tote bag I quilt the fabric with batting but don't add backing. I let the lining be the backing.