Thank You for your kind remarks makes me smile :o)
After I tied (I used embroidery thread) I think I left about 1 1/2" - 2" I hope this helps. I am not sure how yarn is whether it shrinks or not. So that might be something to consider, too. You could leave them longer and then after the first washing see how much/or little the yarn shrinks then cut them shorter if need be.
Glad you are getting your quilts going! You are way more adventurous than I was by putting a binding on them!
Congrats and make sure you post a picture when you are done so we can see!!