I got a little sharpie-happy here. The line above the neckline shouldn't really be there!
Check the back of the block against the front chemise pattern. Since the back is smaller, we're all good. If it was larger for some reason, we'd want to repeat these steps to draft the back.
The back neckline should be higher than the front. I've drawn it in in purple. (Since the back and front patterns of the smock are the same, I'm just making a visual note on the pattern.)
I need a sleeve. It will be a rectangle. I am starting by extending the top bar of my original T.
Mark the length of your sleeve on this line. Your sleeve should be your shoulder-to-wrist length. If you want a sleeve that makes a nice poof at the bottom, add 2" for a human, or 1/2" for a doll.
The width of your sleeve should be at least the same as the widest part of your arm. Complete the rectangle. I've made this a little wider, because Tyler's arms are freakishly long and the piece looked weird otherwise!
It's a pretty good idea to label the pieces.
Next… The Rest of the Draft