If you happen upon a sale of tights that you may want to saver until next season or wear right away, the first thing you should do in either case, before wearing, is to soak them in a tub filled with 1/4 cup table salt and 4 cups of water for half an hour. Rinse thoroughly with cool water and let air dry. The salt will have strengthened the nylon’s fibers  so they will be less likely to snag.