You can machine the lines for gathering with a large stitch and pull all up to make them into pleats.
NOW. Put some stabiliser at the back. Using sewing machine select embroidery stitches and have a go at faux smoking.
This is a quick instruction from memory from Pauline inse books heirloom quilts. Does work on a small project would not like a larger one. I do did smoking on dresses for 3neices and had a wonderful time.
Try amazon for smoking books they do sell old books . I do have patterns but Texas not on my travel list today. PM