Use eye contact as keys. Someone on the far side, looking at you in the base, means that that side is complete. Don't wait for shakes to go through a few people. Use eye contact to initiate transitions and shakes to propagate that information. These are the tricks you learn from experience and other jumpers.
Secret stuff is situational dependent.
It comes with experience and how well you can remember your experience. You can also use some other concepts to make it happen on your dives. This was coined by Ted Wagner. As soon as you're in the air, you're late. Get to your slot, now, faster and faster.