[zz4gta]

In your cockpit, have them switch jobs. It'll go like this:

Everyone is on the rail, lets say starboard tack, and you're about to tack.
1. The first guy, who is sitting the most aft on the rail, is the one who will blow the sheet and trim the main.
2. The second guy on the rail is hot on the first one's heels as he will grab the (already wrapped) sheet on the primary winch, NOT IN THE JAWS.
3. You start to turn as the second enters the cockpit, keep it smooth, and don’t do it during large waves or a wake. Give the trimmer enough time to sheet the sail in by hand. You read right, he or she should be able to get almost the entire thing in before the sail loads up. Only exception is if you’re flying a 150-155, you may need to fall off 3-5* while they grind in the last bit. ANYTHING smaller than a 150% and you shouldn’t need winch handles going upwind. Grinding is painfully slow and it tires out your crew.
4. as the jib trimmer pulls like a monkey on meth, the other trimmer who blew the old sheet will do final trim on the main, from the high side.
5. the main trimmer goes to hike, and the jib trimmer follows him up out of the cockpit but now the order of your rail meat has been swapped, and so will their jobs on the next tack.

Short version: The aft most crew on the rail, will be the one to blow the jib sheet, and trim the main. The second guy in, will trim jib. Then they reverse.