Two versions of the pattern exist. I don't care for the first one, but it exists, I made it, so I'll post it.
#1 - Boxy bodice and rectangle skirt.
#2 - Tapered bodice and half-circle skirt. The skirt requires a bit more fabric, and will take more time/effort to sew. It looks so much better, though.
Two other possible configurations exist.
#3 - Boxy bodice and half-circle skirt. I don't recommend this, it just looks weird.
#4 - Tapered bodice and rectangle skirt. My example has a 1cm longer skirt because I goofed up. This is a good option if you don't want to bother with a curved skirt.
Getting Started
You'll need a disappearing ink marker, less than half a fat quarter of quilting cotton, matching thread, a scrap of tulle for interfacing, two snaps or velcro, and optional ribbon decoration. I recommend some clear fabric paint or fabric paint medium instead of Fray-Check.
Trace the pattern onto the wrong side.
Put the tulle under the fabric.
Sew along the arm holes and neck hole.
Cut notches along arm holes and neck hole. Avoid cutting the tulle, try to just cut the fabric.
Turn the bodice right side out.
Press everything flat.
back view
If one corner looks like it's about to shred, you can use a needle to apply the tiniest amount of clear fabric paint or fabric paint medium to the problem area. It will yellow over time, and will stay tacky and may attract dust, so only put it on the back layer where it won't be seen. Unlike Fray-Check, it will stay flexible and won't turn rock hard. (Fray-Check also yellows over time.)
detail view
Sew up the side seam. Go a little below the waist, so the seam won't come apart where the skirt attaches. Angle the extra portion so the waist stays the same width, though.
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