... cleat them off or whatever you want to do, but make sure there is a bit of slack on the downhaul, maybe a couple feet. Because, as the Asym or spinnaker fills, the halyard masthead will go horizontal or outward, and perpendicular to the mast, which will give the head of the sail proper shape, and leave a bit of room for the sock to bunch up. If you tie the downhaul taught at the mast, you will compromise this head shape quite a bit, choke it and destroy that. Let it float a bit before cleating it off "taught". cheers, John