Mistakes & fixes

Skipped stitches on a coverstitch hem, especially at the seam start, usually come from an unstabilized layer or fabric not feeding evenly under both needles. Use a stabilizer strip and start on a fabric leader.

Loose loops hanging off a serged edge, or an edge that curls and puckers, points to the tension dials being out of balance for the thread and fabric. Adjust one dial at a time on a scrap.