Our city had planned to ban plastic grocery bags a few years ago, but enough people objected that they backed down. I don't get that, but I'm okay with it because I do use one every day for cat litter gleanings, and I guess I'd have to buy something for that purpose if they weren't free. I have made a bunch of cloth bags for groceries, but don't use them all the time. I would use plastic bags to line little wastebaskets also, but can't because one of our cats chews on plastic bags if she can find them.
Sewing a bag is very easy. I just make them about the same size as grocery bags and box the corners. I make french seams or overcast them. I make folded strap handles or sometimes use dollar store dog leashes to create strong handles for them - 6 feet of colorful webbing for a dollar, and they include some hardware that might be useful for something. I like to look out for any printed canvas or duck remnants at Joann's for making bags.