I am against trussing up head sails or main sails with cords. Every little movement "jiggle" will cause severe chafe or in cases cut through the sail in a relatively short time. If there is sufficient warning my approach is to remove the sails. On leaving the mainsail on the boom I use slightly slack shock cord ties to keep it folded in place then rely on the cover to keep it in place again taking care not to truss up the cover but tie/clip it on securely.
The best solution for the head sail is a sock: my friend has one and I can't fault it, easy to put on and easy to remove.
See here for an example:
sailrite.wordpress.com/tag/jib-sock/ the video is worth while.
A properly secured cover is the only way I know to to avoid this:
Important not to truss the sail too tight or the ties will ct through the material quickly.
All the best and safe sailing.