During long passages, we must sail throughout the nights. Our pattern, for two crew, is one sleeps between 1900 and 2100, then sails between 2100 and 2400, then goes back to sleep from 2400 until 300, and then goes back to the wheel between 300 and 600.
We don't go on deck at night, unless it is an emergency, and then we wake the person off-watch to tell them. We always wear tethers (short) at night, and clip onto jacklines that run the length of the deck if we need to go to the bow. Although, we prefer to wait for daybreak to do big sail changes. We typically reef the sail at night, to avoid having to wake the other person up if there are squalls.
During these long nights, we listen to countless podcasts and audiobooks, which we discuss around breakfast in the morning. If we're feeling especially tired, listening to upbeat music, as opposed to spoken content helps.