The pattern is for a size 31 bust, which is a size smaller than I usually sew, but my actual bust measurement. The shape of the dress is meant to be a big rectangle: however, if I sewed it that way, the hip circumference would have been smaller than my actual hip measurement. So I added about five inches total to the width of the lower half, tapering out from the waist to the hip and going straight down from there. I tend to walk with a long stride, so I figured extra room at the bottom couldn't hurt. In the future, I'll add a smidge of width to the upper back, but it's not uncomfortable as-is. Instead of the cuffs that the pattern called for, I added little ties at the ends of the sleeves, because it seemed maybe an inch short in the arms. I think I like the ties better than cuffs, and now the length looks more intentional. :)
A few notes on construction ... I didn't line this dress, so as not to lose the nice drape of the lightweight flannel. However, I did sew the facings down inside because I hate it when those things flap around. The instructions tell you to finish the slashed edge of the cuff (or in my case, just the bottom of the sleeve). They want you to basically just roll the edge up and sew it down, even though you have a 180 degree angle to traverse in the process. Very fiddly -- in the future I'll just make a narrow bias strip to cover the edge. I ended up with a little pucker at the apex of one of the slashes, which you can see in the picture above. And oh yes, total plaid match fail. Though I only tried in the front, I still got it off. Oh well, maybe next time. (And "next time" is basically tomorrow, because the next dress I plan to sew is plaid too.)
My main criticism of the final product is its uncanny similarity to a bathrobe -- between the hood, and the flannel, and the matching tie at the waist, I guess it was inevitable. I plan to make another version soon out of rayon challis, which I hope will have a less bathrobe-y vibe.
Finally, here's a back view showcasing the hoodie awesomeness, which the sun flare only enhances!