I sewed four samples of bias-cut skirts last month using different weights of cotton and silk. Every single one had pleats that bubble out at the top and then flatten weirdly around the hip line. I pressed them with steam, let them cool completely, even used a clapper I found at a garage sale in Portland. My guess is the grain line shifts when I stitch the waistband, but I'm not sure if that is the cause. Has anyone figured out a stable facing trick that keeps pleats sharp before you attach the band?