Weeping willow cuttings root easily, but I don't know about the kind of willow you're looking for. Craft stores like Michaels, Hobby Lobby and Joann's sell decorative bunches of cuttings of both. They are dried, and you'd never expect them to sprout roots, but put them in water and they (weeping willow, that is) take right off. You can even grind up willow twigs, make a tea with it and use the tea as a rooting hormone for all kinds of cuttings