I've done this method a couple of times. What I found helped me was to pin in the ditch on the front through the binding on the back. I pinned very close together, went pretty slowly, and removed the pins just as I got to them. Other than having to go slowly, it worked fine. Even when I'm hand sewing the binding on the back I still pin in the ditch on the front. I don't have so much thread catching on pins issues and I don't get as many puncture wounds (O: if you know what I mean!