Easiest way to add ruching to the side of a dress?

[TracyK]

I have a couple of tops/dresses that I manually 'ruche' up a bit at the sides and suddenly thought - maybe I could try and sew something onto the sides to give them permanent ruching?

Strip of elastic?
Anyone done it or seen a link to it?

There's a link on how to do it from scratch here which explains how to create a ruched skirt.

I've found another technique which invoves basting a large zigzag the width of the ruche, and then pulling evenly.

My first thought was to have two lines of basting either side of the seam, and gather evenly to create the ruche and then sew on a piece of facing to keep it in place.

You may have to try several methods depending on the garment.

Will that result in a loose/irregular ruche - thats what I want it to look like - kind of casually ruffled up the side iykwim?

I may defer to my mil who is a dressmaker and ask her to do it for me!