Create an outhaul take-up If your boat has an outhaul tail coming out of the boom, attach a small bungee to the tail and run it back to the boom. For added length, run in in through a spare reef sheave and back internally to the front of the boom. This bungee makes it easier for the main trimmer to grab it. Additionally, you can create a number system on the boom for repeatable settings.
Prevent Spinnaker Snags Run a small bungee between the shrouds, 12" below where they attach to the mast, to prevent the spinnaker from catching in the shrouds during a hoist.
Avoid deck damage Loop a bungee around your lower lifeline and spinnaker block to prevent the block from banging up your paint. I like to do the same with cunningham and afterguy blocks as well.
Prevent jib lead block damage For boats with non-overlapping jibs and floating jib leads, use bungee to connect the floating lead with the shroud just above it a few feet above the deck to prevent the lead from banging around on the tacks.
Contain dropped genoas If you drop your jib or genoa to the deck when running, run a bungee from the bow pulpit to a stanchion farther aft. Do this on both sides, but on one side add a plastic clip. When you're on a run, connect the two bungees over the genoa to keep it contained.
De-clutter the cockpit Create take-ups for control systems that exit into the cockpit. The control lines usually run through a ferule or fairlead. Use that to run the line back into the boat, where a bungee will pull the slack out.
Prevent overrides Run a bungee across the path of the jib or genoa sheet, one or two feet in front of the winch. Run the sheet under the bungee to keep the line from rising up the drum on a tack. For added chafe protection, sew a rope cover over the bungee.
Prevent knots at mast base while hoisting sails Tie a bungee in a loop around the base of the mast a little above the turning blocks. Run the halyards inside the bungee.