For Louisa's birthday, back in May, I made two versions of the Beach Party Dress by fiddlehead (a free pattern download!). I made the 24-month size and made a couple alterations the second go around.
The first version I made in Blue Wings from the Storybrook collection by Alexander Henry (bought on sale from purlsoho.com) with some yellow checked gingham for the lining (a fat quarter from Ben Franklin). It turned out a little big in the top and too short in the length, so when I made the final party-dress version I took it in an inch or so around the bodice and made the skirt two inches longer.
I also added a panel of the lining fabric to the elastic section in back, which wasn't necessary, but I like the look of it. I used two different prints from Heather Ross's Far Far Away line. It's a very nice double guaze that I also bought at Purl Soho when I was in New York visiting Meredith for my birthday. I store bought pink bias tape which was much easier (and cheaper) than making my own, especially since I was using such fancy fabric. Also I hate making bias tape.
Here's Louisa's dress from her first birthday. It was made from some simple cotton from Ben Franklin using Heather Ross's Smocked Sundress pattern from Weekend Sewing. 12 month size. Super easy, even for my first time sewing with elastic thread.