Yesterday's post on being a successful raider boils down to Respect Another's Time.
This includes the leadership. There are things you DO NOT DO as the Raid Leader. One of them is not tell your team what VOIP to use, and instead make them guess. Another is to say the start time is one thing, then not abide by it. But the biggest is to forget what day in the week it is and decide upon an inappropriate course of action.
Most MMORPGs reset their instance lockouts on a weekly reset. You attempt to go as far as you can before the reset. If you can clear it in that time, reliably, you're said to have that instance "on farm". (Which means that you kill the bosses as if they were crops becoming ripe.) That doesn't mean that all of your team has all that they're after from this instance, just that everyone knows what's what and can do the work to get what they're after.
You don't swing away from that during a reset. You do that after the reset. Resentment builds when you change the plan without need.
Don't be an incompetent raid leader. Be considerate of your team, and of their time- or they will go to someone who does.