So, this is a really really easy refasion.
I started with this skirt.
The skirt was too tight around the waist, so I cut most of the top panel off, leaving enough to fold down to make a casing for elastic. To do this, I turned the skirt inside out, folded the top panel down to the ruffle, and pinned along the lower seam of the ruffle. Using this as a guide, I cut about 1.5cm past the line of pins.
This gave me a panel above the ruffle of about 5cm.
Next, I folded the panel in half, and folded it down over the back of the ruffle and pinned it in place.
Turning the skirt right side out, I sewed along the original line of stitching, leaving a gap of about 5cm to allow me to thread the elastic into it. Looking at the inside of the skirt, this created a casing I could feed elastic through.
I fed elastic into the casing, stitched the gap closed.
And, I had one upcycled skirt - cute pattern, cute length.