I started with Sarah, and chose a nice turquoise brocade for her dress...and got started.
When making the ruffles for the sleeves, I always finish the ends of the ruffles, and attach them a seam allowance distance away from the edges of the sleeves. That way when I finally stitch the underarm seams, I only stitch to the end of the sleeve itself and not the ruffle, so there's no unsightly stitching visible at the wrist. It just makes for a much neater look.
*Note that the elbow ruffle fabric is also hemmed at both ends, and it attached a seam allowance away from the edges of the sleeve. That's so the 'puff' isn't ruined by getting caught in the main sleeve seam when it's sewn. Then the seam is sewn carefully avoiding the puff fabric, and after the sleeves are turned right side out, the two edges of the puff are hand stitched together, thereby retaining a nice 'puff' at the elbow.