The Conduct of the Service requires rehearsal. That is important if you conduct the Service alone. Reverence isn’t aided by your searching for your misplaced hymnal. Rehearse so that you know where everything is, what happens when, and so forth. If you conduct the service with the aid of acolytes or assistants of any type, a rehearsal is essential. A quick run-through in the Narthex while the bell rings never cuts it. Such laziness always produces sloppiness that interjects the personality of the celebrant into the face of the worshiper and distracts him from the object of his adoration. The point is not to produce a flawless service that is overly formal and fussy. The point is to draw as little attention to yourself and your actions as possible. To be prepared is to be reverent of the God in whose presence we serve and respectful of those who have come to hear Him not us. Your goal is to fit in seamlessly and naturally so that the worshipers are not any more distracted by, or aware of, you than necessary.
When it comes to services in other churches (installations, reformation services, etc.) the biggest points of confusion are always how to go in and how to get out. Clergy don’t like to rehearse. They also like to stand in the front with their bellies hanging over their cincture and rock back and forth to the music, cross their legs in vestments, and generally behave as though they are in their own living room instead of in the House of God. Everyone else might do it, but you don’t have to. You can’t do much if you’re just another guy in the parade. Pointing out the sloppiness of others will only earn you their contempt. You just have to suffer it. But you can get there early. You can beg whoever is in charge to tell you how you’re going in, where you are sitting, when you are to leave, and how. It might still be a fiasco, but at least it won’t be your fault. You may even get the guy to think it through a bit which will help everyone.
When you are in charge mail instructions that includes a diagram of the Church with where everyone is sitting, how they are to get in and out, what they are doing during the Service, what they are to wear, and what time they need to be there if they want to participate. Ban anyone from the procession who isn’t there 15 minutes early.