I will start with my church. Alfred Street Baptist Church. Which an old black upper middleclass church in VA.
They started a CAYA (Come As You Are) ministry that meets once a month and has a meet and greet and worship service. It is much less formal and a conversation with different speakers about the realities of trying to live according to christian principles in this new age. It has been a big hit. They have their own happy hours, retreats and balls now.
They put a lot of work into the young adults and singles ministry and have a lot of programming focused on those two groups. Our church is packed out with millenials. As an older married millenial, some of it gets on my nerves so I can imagine what the older church members feel but so far the pastor has been able to manage this balancing act.