Threads Contributing Editor Louise Cutting shows how to maintain a smooth hip curve in skirts and pants. It is how she addresses the issue of a side seam collapsing toward the body at the hip, about 7 inches to 9 inches below the waist, at the junction of the hip and the upper leg.
This is not a fitting problem: Shaping the side seam to follow the exact body silhouette would result in unflattering bumps and bulges. A better solution is to add a stay along the seam in that area, to hold the hip curve shape.
Louise uses 1-inch-wide petersham ribbon, centered on the side seam and stitched to the seam allowance edges. This easy fix can be applied to a skirt you are sewing from scratch, or to an existing skirt, including ready-to-wear garments.