Many quilt magazines and web sites have lots of free patterns for totes, McCall's comes to mind. For tote bags, I like to use upholstery fabric or fabric for outdoor furniture. You can often find heavy weight fabric in the clearance aisle of your local fabric store. When I make purses, bags, I have found that using plastic canvas, covered in batting and then matching fabric to the inside holds up well. The other thing you can use are the plastic cutting boards that you can find in dollar stores, as they are sturdy also.