I get most of my containers at Good Will and Salvation Army stores, usually for $3 or less apiece, and often find bunches of unused silk flowers there, too. But great buys can also be had at the end-of-the-season sales at local garden centers and craft stores. And there's nothing better than amassing donations from friends. Most of the containers above, for instance, were donated to the cause by my friend Tess.
Of course, if you want to do this in any volume, it takes quite a collection of both containers and silk flowers. My husband was kind enough to build me a wall of shelves in the garage to house mine. And he usually manages to bite his tongue as the scene gets more and more chaotic and spills over into the basement -- not to mention the kitchen, which becomes my washing-and-arranging workroom one night a week.
But I guarantee that it's worth it. My elderly friends look forward to their new arrangements each week. And between visits, they're reminded that someone is not only thinking about them, but is making something special just for them.