When I was a kid my grandmother showed me how to sew hemlines properly. I have no idea what the stitches are called, but it works just fine. The red taffeta dress I'm working on of course needed to have the hemline stitched by hand (I really didn't want a visible seam at the edge!) so I thought I'd take the time to show you what my grandmother taught me.
First, you do a tiny stitch above the hem, from the right to the left.
The result is a very flexible seam that is hardly visible from the outside. Do any of you know what the stitches are called?