If you are accomplished sewing, tie the two tails of elastic thread alongside one another (on the incorrect aspect of the fabric) and trim any added thread. Preshrunk/ prewash the fabric in advance of smocking. It can be true that unwashed material appears to be like best when smocked but https://brooksztjvf.ampblogs.com/the-smart-trick-of-smoking-thread-that-no-one-is-discussing-69368212