Making a Muslin for New Look 6557

I've decided to make a muslin of my first dress, since I really want the finished product to be perfecct. I started on the muslin for the blue dress today. I traced the pattern (I don't cut into my patterns, because I'd like someone else to be able to use them later), cut the pieces out of an old sheet stained with ink that I saved for just this purpose, and started stitching the bodice together. This dress seems to just sort of fall together. I'll probably finish the muslin tomorrow and see how it fits.

I thought about lining the dress, but I'm wondering if I can't just finish the seams nicely (I just looked up a tutorial for French seams, and they seem pretty easy). That way, the dress will be lighter for the hot weather. If the muslin fits and I have time, I'll start cutting out the fabric for the dress tomorrow too. So excited!