Jen Kingwell's Postcard Projects are simple and wonderful. Use the template to cut a variety of fabrics to make a scrappy, happy quilt! The three shorter sides will be 1.5" each and the long side is 3" when finished.
The Half Hex Postcard Project #13 can be stopped at any size. Instructions are included for hand piecing but can also be completed using a machine. But really, this is more fun to hand piece :-).