if you can plan in advance (330 days), then i'd try to use ff miles, if you have them. check with the airline whose miles you have to be sure it is 330 days (they vary). otherwise, it's one of two directions: book as early as you can and then don't look back (probably the best idea), or wait until the last minute when airlines will tweak fares down to fill the planes, and then use a last minute site.