EDITED 9/23/10: The full detailed directions for this alteration are now available on the website here at LearningAlterations.com
Today I altered a gown for a bridesmaid who has recently delivered a baby. She bought a dress that was big throughout the belly area, so we had to take in the bust. It was gaping open so badly that you could see right down into it.
First, I had to pin out the amount to be taken in. Since it was such a large amount, I decide to take it out of four seams, 2 bust and 2 side seams.
Next, I separated the lining from the fashion fabric. This involved removing the stitching as well as the understitching.
Since the dress had boning in it, as any well made formal will, I removed the stitching that attached it to the seam allowance. In some dresses, it is attached to the lining, but not here.
I then took in the side (or bust) seam, graduating the new seam into the path of the existing one, making sure to keep a gentle angle. If you take in a lot, in a short amount of length, your garment will be pointy at the seam.
After that, trim the seam allowance and press the seam open. Then reattach the boning to the seam allowance. Now I repeat all these steps with the lining.
The next part requires a little creativity, especially if you have taken a lot of the seam in, as shown here. I have to stitch the neckline back together, but the new edge is uneven, because of the newly stitched seam. You could draw a new stitching line with chalk or a disappearing marker, but I just eyeball it. Just make sure all the layes are caught in your stitches. Sometimes you can't see this until you turn it right side out.
The finished seam should look like this. Rip and redo if you have to, to get a smooth line.
Now I can add understitching that will meet the understitching that remains. Time to press well.
The finished garment should lie smooth and fitted against the chest area.