these are the bags i made for thereusable shopping bag swap on craftster. i used a green floral/polka dot fabric on both bags [it might be hard to see, but the polka dots are made up of tiny flowers], and lined each with a contrasting fabric, and made coordinating straps.
each bag is about 14" wide & 20" long, with 14" straps.
black floral with green floral/polka dot lining & straps
green floral/polka dot with brown floral lining & straps