I used a combination of this and the other two pillowcase dress tutorials I have pinned. Honestly, I don't love any of them, but by reading through all of them I was able to make a dress I really liked.
So easy to sew ~ It's just 4 rectangles. Measure shoulder to hem length, then girth at widest part and divide by 4. Add seam allowance. Sew allowing for neckline, arm holes. No pattern needed. 1/2 hour, max!