For the skirt of my dress I wanted an A-line. This means that the dart is rotated so that the side seam will be wider. The picture below shows the bottom part of my sloper. When the dart is cut and the dotted line below you can fold the dart lines together, creating the A-line shape.
There is one disadvantage though when you have a large difference in your hip/waist measurements. The dart on the sloper is wide, which makes for a rather steep angle when you fold the dart out. Making it to a nice curve will shorten the waistline quite a bit.
The solution is using two darts. On top is the original sloper as above, below the same part of the sloper, but the darts are changed in two smaller darts.
After the darts are rotated out, the curve of the one with two darts is much smoother. Below I’ve added a red line indicating the one-dart version.
Removing or adding darts is always a design decision and (for me at least) there’s no right or wrong. There will be other ways to do it but this is how I do it.
The dress is coming along nicely. hope to show results soon.