She first made a grid, marking the fabric every 2" with an air/water soluble marker. Then, starting on the left side, match one of the markings with the one directly to the right. With a needle and thread, stitch the two together a few times to make a pleat.
After finishing your stitch by knotting it off, continue matching dots in a vertical column, skipping a mark in between.
When you are done with your first vertical column, start on the next one! Find the mark you skipped between pleats, and begin the whole process again there. As you match this mark to the one to its right, your pleats will begin to make a diamond shape.
After a few columns, you will totally see the large-scale, super-simple smocking take shape. And you will be super impressed by your mad smocking skills. Something to remember is that when you do this, it will shrink your starting piece of fabric considerably. To be safe, start with a piece of fabric twice the height and 4-5 times the width you want the finished project to be.
While it is a really time consuming thing, it has a really glamorous effect with fabric. Right now I'm working on doing smocking for the front of a pillow, except I did my grid every 1" so it is a little smaller scale. And I added pearls. I'll show you as soon as I'm done!
This picture is about a fourth of what she actually did. Amazing. Can you Imagine this at the top of a drapery panel? Luxe, I know!