Double sided fleece blankets are easy to do. You cut fringes around all sides (measure so both pieces of fabric are cut the same), then double knot the fringe. Voila! You're done!
Some kids will be interested in a more advanced project piecing a quilted throw. Blue jeans can be cut (pattern optional). Then instead of having the seams on the inside of the quilt, leave the seam allowance on the outside of the quilt to allow it to fray. (It adds an unusual texture.)