Yes folks, your eyes do not deceive you, this is dental floss. I finally tried out a sewing tip that I learned about on an episode of Simply Quilts with Alex Anderson on HGTV. Rather than making gathers with the traditional method (sewing two lines of long straight stitches above the gathering line and then pulling the bobbin thread S-L-O-W-L-Y and careful not to break the thread) I tried this simple tip.
Step one: About 1/4" above the stitch line, sew a zig-zag stitch OVER the dental floss, be careful not to catch it in the stitching - couching it. Leave a long tail at the end. Flat dental floss works great.
Step two: Gently pull the dental floss (making sure not to pull it out from the start) to make your desired gathers. Sew along the stitching line and then gently remove the dental floss from your project. Voila! Perfect gathers every time.