National Public Radio’s Planet Money’s Life of a T-shirt Five short videos (approx. 1:30 min. to 6:22 min.) comprise this excellent series developed by NPR's Planet Money team. The chapters address cotton, machines, people (workers in factories), boxes and us. Readings are available with each of the chapters. (Grades 7-12 and adults) This series addresses complex issues, such as child labor and worker rights.
Other resources, good for younger audiences as well, include this reading and a graphic by Evergreen Design Company depicting the life of a t-shirt. Consider copying this graphic multiple times, then cutting apart the elements. The arrows aren't necessary, nor is the Reduce, Reuse, Recycle element. Have students work in groups to put the elements in the correct order. (Some stages occur multiple times in the life of a product, such as transportation. The students could draw more symbols for those, if you wish.) We recommend that you ask the students to put these in the correct order, linearly. (Until we make significant changes in the way we produce products, most do end, rather than continue in a cycle.)
After the students finish, then give them blank sheets of paper in a similar size of the elements they've already placed. Ask them to think of ways to reduce environmental impact along the chain of production/life of a product. Encourage creativity! Solar-powered manufacturing, hybrid tractors (similar to hybrid cars), and--best of all--buying only the number of t-shirts you need and really want.