Mistakes & fixes

Extending sleeves that fall short requires a deeper hem let down, an added cuff, or a contrasting fabric extension at the wrist. Check there's enough hem allowance before promising extra length.

Adding room to a garment that's too tight relies on unpicking the existing seam and resewing with a narrower allowance, which only works if enough seam allowance remains. Check the seam before promising this alteration.

A knit edge that ripples into an unwanted wavy, frilled finish happens when fabric was stretched while being serged or hemmed. Ease the fabric through the machine without pulling and use a less dense stitch.