Now it's time to discuss other areas of rounding in our backs. Depending on the shape of your back, how erect you are - how curved you are - how prominent your back shoulder blades are, you may need a shoulder dart. Sometimes it doesn't always appear that obvious when looking at your back...not that you generally look at your back unless you've got a 3-way mirror...and then again, sometimes it is more obvious.
In taking a look at this photo, you'll see diagonal folds in the back bodice going from the underarm up toward the shoulder blades. This is saying that she's rounded across her upper back and that back shoulder darts would help to eliminate them.
Here is what the bodice back looks like with the simple addition of a shoulder dart.
Here's what a pattern looks like during the process of adding the shoulder dart.
Adding A Shoulder Dart.
And for those of you who prefer to watch this process, here is the detailed video: