Great tutorial! I do mine slightly differently, I only sew one underarm/sleeve seam, then I gather my skirt material with my ruffler or gathering foot and sew it on to the bodice. Then I sew the remaining underarm/sleeve/side seam last because I don't like to attach the skirt in the round (just like I don't like to attach sleeves in the round). I guess I'm just lazy this way. Of course, my method has backfired at least once where I gathered the skirt up to tightly and it didn't fit.