Ever find yourself in the woods or at the range ready to shoot or hunt and notice that your nock has moved? Here is a simple and easy solution. I always carry a couple of feet of serving thread in my pack or quiver to solve little problems. You simply use the serving thread and tie over hand knots in front and then behind the string alternating back and forth three to four time each above the nock this will keep it from sliding. You could even do this once you get your nock set so you do not have to worry about it moving.
Another use for the thread is if your nock comes off of your string unnoticed. You will first find out where your arrow should go, usually there are some marks on the serving from your nock. The just as above start tying overhand knots in front and behind the string to make a nock for your arrow. Some people only use a serving nock anyway.
I would reccomend shooting a practice arrow or two after you do this in the field.