I'm afraid I cheat and purchase double-fold bias binding in a coordinating color. Yes, perhaps that's the lazy way, but I am perpetually slow. If your potholders have curves, though, I do have a suggestion: I machine baste in the fold so that when applying the binding, I can pull the thread and ease the binding around the curves. Also, when I machine stitch the binding to the top, it really helps to make a pretty top-stitched binding, without struggling to make all the curves!
Jeanette Frantz