Have a missionary of the week. I usually read the most recent prayer letter from our missionary of the week on a Wednesday night.  Then having read the letter I would not only encourage our church to pray for their special needs, but to send them an email letting them know they were our missionary of the week.  For just a moment put yourself in their shoes.  If you were thousands of miles away from family and friends would you not appreciate and be encouraged by such an email?  I would also copy their most recent letter to the back of the church wide prayer list so every member would have a copy of the letter to take home themselves.