For those of us who actually still use hank-on sails:
I attached a 2' tether to a bow padeye with a simple bowline. The other end has a snap
shackle. Before attaching/disattaching the halyard to the head of the sail I snap on this tether to the halyard. My halyard is never disattached from the boat on either end. Ever. This eliminates one way of losing a halyard to the masthead.