1) The leader must prep to give announcements. Do not do announcements off the top of your head. This communicates to your group that what you have to say is random and unimportant. Even if you just write them out on a sticky note or a pad of paper, it will be helpful for you to think through what you want to say to your group and why. This will also remind you to gather all of the relevant details that go along with any announcement such as dates and times. This will also help you to not forget certain important announcements.
2) Announcements should be relevant to your group. People do not need more information about more events. It will help your small group to know why your announcement is being made in this group context. For example, "This Sunday morning, our church is having a special Service and Simplicity day. This will be a time where we will have various activities having to do with gratefulness and simplifying our lives. I wanted to let you know that our group will be helping out with receiving stuff at the Goodwill truck from 10-11am. Please let me know if you can join us."
3) A personal or emotional connection can be helpful. Knowing why a leader is excited about something helps me to be more intrigued about something that is being announced. Therefore, saying something like, "I am really excited about the Christmas Eve service because I really like having a spiritual focus of worship before spending time with my family on Christmas day. It will be at Foothill Covenant Church at 5pm" is better than "The Christmas Eve service is happening at Foothill Covenant Church at 5pm. You should come."
4) Do not rely on announcements to invite people to things, especially something that is happening outside of the normal schedule, such as a conference or a service opportunity. Knowing about something and feeling invited to participate in something are two very different things. If there is something special coming up, you might want to mention that you (or someone) will be following up with them personally or give people a practical way to respond (like a sign up sheet).
Do you have any other thoughts or ideas about how to make small group announcements engaging, memorable and helpful for people?