I was able to look at two dresses, and at my guess they were previously worn by the same woman due to the similarity of style, size and fabric choice - which is always an interesting thing to consider. They were both evening dresses, and made of similar fabrics (in terms of the weight, fibre composition, and the woven metallic thread design). Very interestingly, between the two dresses there are elements of the cut of my dress to be found.
What I found really notable, firstly, was the seam finishing. I had expected French seams to be used but in fact both dresses had seam allowances (which were not noticeably narrow, 1/2"-1") which had been overcast by hand to prevent fraying. This would reduce the amount of bulk caused by a French seam, which would be noticeable on the right side of the dress when worn as the fabric lies so close to the body.
All raw edges at the neckline and armhole were finished by 1cm bias binding, made from the same fabric as the dress. The dresses closed either with a side placket and hooks and eyes which were very neatly inserted with the edges of the hooks covered by a piece of white tape; or with covered buttons down the centre back.
Some seams, especially the angular ones coming across the body, were topstitched for emphasis. Also I found it interesting that the long, lower skirt pieces sometimes had parts added in; that is to say, there were joins in the fabric where excess had been sewn in due to it being difficult to cut out the whole piece from the fabric. As the dresses were shop-bought and not home-made endeavours, this showed me that it was perfectly acceptable to have a join in the fabric.