My crew sets rules and follows them.
-Call out Deaths
Calling out deaths just avoids people assuming someone is there as back up. Knowing who is alive and who isn't ensures that whoever is operating the ship will disengage if need be. Too many crew deaths leads to a ship being overwhelmed. Disengaging until players come back is more ideal.
-Call out Actions and reply with confirmation
I find it helps that people call out what they are doing because it avoids stacking unnecessarily on a task, while also ensuring a task gets done. Before we made that rule we noticed that people would assume something is getting done, like patching, when in fact it wasn't. For confirming, whoever is downstairs patching, should be assessing the damage. They should announce if they need buckets, and if so, who ever responds to the call for buckets tells them they are on buckets.
-No more than one boarder.
Simple enough, too many off ship leads to a ship sinking real quick.
Its kind of hard to put in words what we do, a lot of it is just natural considering we have sailed together for so long. The rest are just tips on efficiency. Before engaging in fights, we always lift sails in order of front to back. This gives the captain the option to only worry about their sail and surrounding area. Also stick to one side when raising. Too many people swaps sides for some reason, and all that does is screw up the other guy making it take longer to lift.
Do what we do, "Pack a lunch." By this I mean before leaving the ship for combat, boarding, or any activity involving an enemy ship, leave with food. Only food as well, leaving inventory space for planks and cannonballs allows you the option to take theirs. Remind your teammates as well.
The only set roles we have is a boarder and whomever is piloting. The rest are either cannons, defense, or repairs. This is where calling out your current task comes into play. You fill where is needed. I'm not a fan of designating other roles, it feels too rigid and lacks the flexibility that comes with rotating tasks. However, this only works when everyone is on the same page and is willing to comply. This is more of a long term crew strategy, rather then random crews.
You may want certain sail positions with a name to expedite the process. We have one named position, we call it "Sails to stupid." You use it when sailing into the wind. Ship speed can be funny sometimes, but this position manipulates the physics and makes the ship faster in that wind type. It shouldn't work, hence why we call it stupid.
There is probably a myriad of ways to go about this. This just works well for us, but the biggest thing you can do is just be a team-player. Don't play the blame game when you sink. Take a step back and look where you personally can improve.