Here’s an unusual business model: Encourage customers to copy your product and make more.   Bags by U is a youth group that sells fabric grocery bags and beeswax wraps — and helps people make their own. Its goal is to keep single-use plastics out of the ocean, and all of its proceeds go to environmental education and charity.   “The public should use them for reducing our single-use plastic and trash to reduce climate change and global warming,” says Sophia Morris, 14, who started Bags by U last year. “The true reason why I do it is because there are so many animals dying every year from water pollution, air pollution — all the pollution you can think of. It’s really sad.”   You can buy the produce bags and wax wraps online at rycyclebags.com or at The Recology Store, which has locations in Shoreline, Burien, Issaquah and Bothell. Beeswax wraps are $5 each, and bags are $8 each or 4 for $24. Bags by U also holds events where the kids bring sewing machines and people can make everything for free. Or go to BagsbyU.weebly.com for YouTube tutorials on how to make your own.   “It only turns out that we sell them because demand is high and not everyone wants to make them,” says RyAnn Morris, Sophia’s mom.   After coming up with the idea of making bags, Sophia and her mom took sewing classes and her grandmother bought her a sewing machine. Now Bags by U has two groups: The Burien group meets at her house, and there’s another group that meets at Queen Anne’s Cascade Parent Partnership, where she takes classes with other homeschooled kids.   “We started making them because I was inspired to try to get our family to be zero-waste and produce less trash in general,” Sophia says. “It was a step in stopping plastic pollution and getting a more healthy environment.”   The kids are using the money they raise to go on a Salish Sea expedition, and donating the remainder to The Ocean Cleanup.   Another big part of Bags by U is education. The kids make presentations about why environmental sustainability is important and teach people how to recycle properly.   “We’ll play a game,” Sophia says. “We’ll say, ‘Where do you think this goes?’ ” Start with a big pile of trash, and sort it into four piles: compost, recycling, TerraCycle and landfill.   The Bags by U kids also took a field trip to PCC Community Markets to see how they could shop zero-waste. They walked through all the departments of the grocery store with their own jars and bags to refill, and explored eco-friendlier alternatives like bar shampoo.   RyAnn and Sophia went through their whole house to figure out how to reduce their waste. They only use vinegar and baking soda to clean. When they’re out and about, they bring their own water bottles, coffee cups, bamboo silverware and of course, their own bags.