Ever since I read the KwikSew newsletter (sign-up for it) last week I wanted to try this pebble edging (here's a link to all their technical articles). It is super easy and cute. I used it to do all the edges of the cross-top part.
You use this stitch. I never use it on my machine because it is backwards for the blind hem stitch. I use another stitch for that. I don't really know what this stitch is for but it works great for this. You make sure the zig-zag thread goes off the fabric and you tighten up your tension just a titch. I used an orange rayon thread on the front so that it's pretty and shiny. The back, shown here, just got plain ol' orange thread.