Hi,
I'm not sure if anyone has shown you how to use a fork pin. Try visiting the www.quiltcetera.com website for some tutorial photos. Personally, I use the folk pins the opposite way (so the points of the pins, rather than the "head" is sticking out of the fabric.
BTW, we call fork pins "mortgage pins" in my neck of the woods, the idea being that they are so expensive you need to take out a mortgage to buy them! :) Good luck!
Maria