Pillows or toys from old jeans and pillows or blankets (problematic to make for kids). "The cutest denim whale from old jeans. Great tutorial, instructions in Finnish, but the pictures actually tell the whole thing.
Recycled jeans notebook or planner. Use a regular notebook, and cut up them jeans that the kids have outgrown. Also a good idea: using a larger notebook and a patch/screenprint from an old favorite shirt.