To start off, I figured out where I wanted to make my waistline and pinned all around
Since this dress had multiple layers of fabric, I pinned the layers together and then sewed a straight line the whole way around to secure them together. Then I zig-zagged over the edge to keep it from fraying.
Next I started securing my elastic to the dress. This was kinda tricky because I didn't want the dress to bunch up any in the front, so I pinned the 2 ends of the elastic to the dress and then started pinning around as I went. I made sure the front of the dress laid flat and that all the bunch was going to end up in the back. The tricky part about elastic is that you have to stretch it as you sew.
Ta-Da!! Elastic secured!
And that's it! I hope you are able to use this refashion to get some more life out of an old dress that you have floating around.