Preethi from WIDI shows her favorite method for gathering fabric, which uses three rows of basting stitches. Two rows of basting stitches are in the seam allowance, and the third is just on the other side of the seam line. The third row of stitches helps keep the gathers from pushing flat while they’re being sewn. This extra row of basting stitches requires a little bit more effort, but the prettier gathers are worth it. Get the tutorial at WIDI.
[photo from WIDI]
Joyce says
Another easy way to gather fabric is to cut a piece of clear swimsuit elastic to finished size, pin to garment at half way mark and again at quarters. Zigzag on elastic and fabric (clear swimsuit elastic is the only elastic you can sew through without damaging elasticity) and like magic your gathering is done without trying to gather evenly and dealing with the thread breaking.