I challenge you to start on time tomorrow.
Whatever you are in charge of... start it on time. If you're in charge of when your service starts, do it when you say you're going to. One reason people continually show up to church late is because they've shown up on time once or twice and you weren't started yet. If you say that church is at 10am, start at 10am! It builds trust with your church.
Maybe you aren't in charge of when your service starts. How about your worship rehearsal? If you tell your team you're going to do a run through of your songs at 8am, start at 8am! Not only does that reinforce the expectations you've set - it also respects the time of the people who HAVE shown up when they were supposed to.
Before you lead tomorrow, check the clock and start on time!