"I've told you a thousand times" is usually an exaggeration, but maybe it shouldn't be for church leaders who are leading the Sunday morning Worship Service.
Most new people in church start by attending the Sunday morning service. They have decided that they want to go to church. They may have heard from a friend or neighbor that this church is good. They may have checked out your website and Facebook page. They may have carefully planned out their first visit. And now they sit in the fourth row from the back, listening and looking around to try to figure out what is expected of them.
I once attended a Portuguese Catholic funeral service of the father of a member of our church. I am not Catholic and do not know the traditions, much less the traditions of their funerals. I am not Portuguese and am not able to understand anything said in that language. My wife and I were constantly looking around trying to decipher what was expected of us: when to stand, when to sit, what to do.
When new people come to church, especially if they are in a church for the first time in their life, they are trying to understand the "language" of the church. They too are trying to figure out what is expected of them. Do we join in with the "karaoke" singing, as people sing along with words on the screen, or do I just allow the band to entertain me? What do I do when they pass the baskets up and down the rows?
In one church, they passed a binder with pages of information for each person to fill out as the singing was happening. No explanation was given, but everyone faithfully filled in information and then passed the binder to the person next to them. The poor first timer is flooded with questions. What is this for? Why are they asking for all this personal mailing information? What will they do with it? Do I have to fill it out?
We need to explain things as they happen in our services. Tell people why you are doing things and how you are inviting them to be involved. This is not just for the newcomers, but also for the people who regularly attend. Why do people automatically stand to sing? Do they have to, or is this an option? What is expected of them when the offering bag or basket is passed around? Are they supposed to answer the questions the preacher asks in his sermons? Or are they rhetorical questions with no answer expected?
One church had different colors of cloth (like a small towel) draped over the ends of the pews. Sections of the church had the same colors. Toward the end of the service they explained that they were encouraging people to get to know the people in their "section". They explained that some Sundays they had special coffee times for certain sections at their little "cafe" in their entry area. Each Sunday they would explain what they were hoping the people in the congregation would do. And the people began to do what was asked of them. It was explained and explained again. People understood, and then actually began doing what was asked. It worked because they explained it and explained it and explained it Sunday after Sunday.
Do not assume everyone will know what you want them to do, whether it is in the Sunday service, or in any other aspect of the church. Good leadership will explain clearly what is asked of people again and again.