I have made snack baggies before and love them. I use them for lunch snacks, but also for little sewing gadgets, or jewelry when traveling. Here is the tutorial I follow for the snack baggies from Owen's Olivia: http://owensolivia.blogspot.com/2011/08/olivias-snack-bag-tutorial.html
As for the lunch bag I followed a tutorial from Craft Buds: http://www.craftbuds.com/car-trash-bag-reusable-lunch-bag/
-a fat quarter of fabric (I used about half) These are those little folded squares of fabric that are used for quilting I think.
-muslin for the lining
-fusible fleece (I did not have interfacing, so I used this and it seemed to work just fine)
-sewing machine, thread, pins
Lunch Tote Tutorial:
So I basically followed the tutorial on Craft Buds, but here are my pictures anyway! Also, I did line my bag which they did not so I will try and explain how I did that.