A great small group idea is to base a small group around a group of people going on and supporting a mission trip. If you have a mission trip going somewhere in 5 months, for example, then forming a small group with the people going on that trip and people who want to support the trip through prayer is a great way to make the mission trip more successful.

Build Relationships: Having these small group meetings will help to build relationships in advance of the trip. People will get to know each other gradually and this will help when it comes time to go on the trip.

Get Prepared:  A mission trip based small group will also make preparations and education for the members of the group much easier.  The weekly meetings can cover a wide range of topics like what to pack, what immunizations are needed and their timelines, what documentation is needed, and more.

Get Educated:  These small groups can also go a long way in educating the group members.  Missionaries can be brought in to talk with the group so they know what to expect and how to be most effective.  You can learn about cultural differences and language differences that you need to be prepared with.