Like most sock knitters I have a favourite style of sock, in my case top down, heel flap and gusset wedge toe. Which is basically what the Firefly sock is. When I got to the heel flap, the instructions were to put two garter stitch stitches on each edge of the heel flap, rather than slipping them. So I did.
When it came time to pick up the stitches, all I had to do was slide my needle through the garter stitch bumps. Look how neat it is! How pretty! How perfect! Genius, really.