Last night I made a second muslin of McCall's 2206. I am using a size 18 pattern, even though I normally use a size 16 bodice and even a size 14 at the shoulder.
For this muslin, I have made a 5/8" princess FBA, and I have added 1" of length at the waist. You can see some puffiness (extra fabric) in the back bodice, and if you look closely, you can see extra fabric puffing on the side right in front of my arm. Luckily, the skirt fits perfectly.
After staring hard at this in the mirror, I decided to try something new (to me) to get rid of all that extra room in the bodice. I didn't think taking in the side seams was the best answer, so I pinned and then basted a 1/2" "tuck" from the shoulder seam all the way to the waist on both sides of the front (just inside the princess seams) and the back, effectively removing 2" from the total circumference. When I tried it on again it seemed to have done the trick. I have an idea for how to adjust the pattern to compensate for the "tucks," which I'll have to share next time.
I plan to add just a little more length to my FBA, and I need to check the fit of the collar and sleeves, but I'm almost ready to start on the real dress. I'm thinking about using a dark red suede cloth (I think that's what Hancocks calls it) from stash.