On this outer half you need to create the illusion of the outer layer turning back and there being a second, lacy layer poking out underneath. We'll do this by lining the front section of the outer layer and adding little triangles of fabric to imitate a middle layer.
1. Lay the centre front lining pieces that you cut against the centre fronts of the outer layer, right sides together. Just as you did with the inner half, sew along the centre front edge and halfway across the top, press, turn and press. Baste the loose edges down.
2. The lacy middle layer is a just a triangle of fabric, sewn to the lining by hand so as not to let the stitching show on the outside.
a. Work out its exact shape by laying the "outer" and "inner" front pieces together with the "lapel" turned back as if the bodice was finished. Then insert a piece of paper between them, slowly cutting it down to the size and shape you want. Trace it onto a new piece of paper and add seam allowances.
b.Cut two pieces of scrap fabric in this shape, then turn the pattern piece over and cut two more in mirror image.
c. Sew the two pairs of scraps together, turn and press, and handsew scraps of lace to the outside.
d. Place the finished triangles on the lining side of your centre fronts and handsew down, ensuring the stitches don't show on the outside of the bodice outer layer.
3. Then sew the whole "outer half" of the bodice together.
When you've sewn all the seams and put these four layers of fabric together, you'll end up with little ridges each side of the seam where all your seam allowances end. Counteract the bump by trimming the allowances to different widths.
After sewing and pressing a seam open, trim one layer of the flappy seam allowance edges but not the other. For extra couture points, hand sew the edges down loosely to the cotton layer so that they don't all bunch up and create lumps and bumps when you put the layers all together. (That's another advantage of the cotton underlining - you can sew seam allowances and hems to it and hey presto, no stitches show on the outside.) Yes, this all takes time and patience, but it's a pride thing. You'll know you did it. You'll see the subtle difference. You'll know you did couture, and not just dressmaking.