I have these photos ready so I'll add these.
I had this dress and unfortunately the top of it had begun to deteriorate to the point of a peepshow; not quite the attire I aim to fashion myself. This picture is from 2007 when Steve and I took my brother into the city to visit the National Constitution Center. I thought I could alter it to make a pillowcase dress for Scout and was pleasantly surprised at the ease of it's creation.
I made no measurements; this was a "I must craft something right this minute" so I just went for it. I cut off the top of the dress just under the zipper and then used this tutorial to get an accurate armhole size. I cut off the ribbon ties to use for the pillowcase ties later on.
I pinned around the armholes and sewed through. I was in such a determined state I didn't even change the color of thread on the machine, it was teal and I just left it in there. After I sewed the armholes I did the front and back top hem leaving a channel to pull the ribbon through, and then pulled the ribbon ties (from the original dress) through to make the two ties.
It was easily one of the quickest and easiest projects I've done, and it satisfied my craft fix for the night. I call that a success. Accordingly, the true test was if it fit the intended model, and as you might tell, she quite enjoyed it. I was even able to have her wear the beloved red saltwater sandals. Any occasion to wear those is picture-perfect in my book.