Step by step

Here is the step-by-step procedure, which is also shown in our video :
  1. Flake main halyard, so that it won't foul and can’t get washed overboard.
  2. Ease main halyard to take all load off the sail.
  3. Take in the slack of the boom preventer in any kind of seaway where the boom might bounce around – this is necessary when short-handed. If enough crew is available, one should man the sheet during the entire manoeuvre, playing the sail, taking in slack and easing when needed and being aware of clew and halyard tension.
  4. Pre-tension the active clew line to give some leech tension.
  5. Lower main halyard only as fast as you bring in the tack line (if used) and the clew line so the sail comes down under control like a window blind. Avoid letting the leech flog. If sailing solo or short-handed this might have to be done in alternate stages.
  6. As you bring down the sail, take in the slack on the other clew lines to avoid them fouling on the boom end.
  7. When the reef tack is down, attach the shackle or put tack ring hook.
  8. Rehoist main halyard for proper tension.
  9. Tenion clew line, easing the mainsheet to so the boom rises up to the new clew. Check that the loose sail cloth is not drawn into the clew block or that there is line chafe on the sail.
  10. Trim main sheet.
  11. Reattach the tack line to the next reef cringle aloft.
  12. Adjust leech line if need be.
  13. Secure all clew lines and the halyard tail.
Taking a reef out is pretty much the reverse procedure. By the time the wind has dropped making more sail should be a very relaxed manoeuvre. In all things, be meticulous!

Exerpted from the storm sailing article at Yachting World .