Make sure everyone who is attending knows what time the ride leaves, and that if they aren’t ready for “clutch out” at a given time they’re going to get left behind. In my experience it only takes one instance of this until people realize you’re serious and “clutches out at 9AM” doesn’t mean you can arrive at 8:57 and then take your helmet off and go get a cup of coffee.
Similarly, everyone should know things like where the ride will stop, what route you’re taking, where the ride ends, whether there will be food available. I also make it clear that I won’t ride with folks who are not on the same page as I am when it comes to wearing motorcycle gear, and drinking and riding. I’ve seen too many people’s insides on the outside, and if you’re not taking your safety seriously, I don’t want to ride with you. All of this happens in the organizational stages of the ride, well before we’re all standing (or sitting) in the parking lot.