Our technique . . .
Use your main halyard as primary and your jib or spinnaker halyard as the backup, keeping both attached to the bosuns chair at all times. Use your halyard winch to haul a lightweight person part way up, secure the main halyard, and then take in the slack on the jib halyard. Continue doing this all the way up. When you get beyond the point where the jib halyard is attached to the mast on a boat with a fractional rig, you will actually have to let out the jib halyard a bit to let the person get to the top of the mast. Reverse the process coming down. Make sure the halyards are run through a line brake or other device to keep the halyard from letting go at the wrong time.We also attach a tether off our safety harness to the bosuns chair, run it around the mast and back again to the bosuns chair to keep the person from swinging if the boat gets rocked by waves. A third person to keep an eye on the climber while one of you is grinding on a winch is also a good idea.Hope this helps.Gary WyngardenS/V Wanderlust H37.5