It takes 5 lbs pressure to cut off the jugular, 7 lbs pressure to cut off the carotid. You want to aim for the latter. That means first locating your carotid arteries. Put your thumb at the corner of your jaw and follow that big tendon/muscle/whatever down about an inch. You will feel a little nook between that tendon and your trachea. If you press hard there and hold your thumb there you will feel a very strong pulse. That's your carotid. If you compress them on each side hard enough simultaneously you will feel a lightheaded, sparkly, cold sensation and nearly pass out almost immediately. If you can replicate that with your ligature you have it correct.