Headsail furling: Best practise
You should unfurl the headsail after you''ve raised the main and are sailing.
Put the sheet on a winch and start pulling out the sail. Once you get it out a bit, the wind will do the rest.
The important thing to remember is to keep the furling line under a bit of tension as the sail unfurls. As the sail unfurls, the furling line is wrapping onto the furler drum. If you just let the sail fly out with the furling line slack, you''ll get riding turns on the drum and you won''t be able to roll it back up.