Here are four quick tips from Prayer Guide Lowell Snow:
Keep the request time to a minimum by having a prepared list and asking only for updates and additions. Take notes as requests are made and don't enter into 'discussion' about each request. If there's too much discussion, interrupt and ask if you've got the information correct; then read from your notes. If there are no corrections, ask for the next request.
Begin the prayer time with a favorite scripture. After they bow their heads, ask them to listen to the words of this scripture. If it's short, read it two or three times. You want the prayer time to be a two way conversation with the Lord and this lets Him speak first.
Use prayer by suggestion to guide them in personal prayer. After you finish the scripture, suggest that each person pray silently about the following things. Give them an appropriate time between each suggestion:
praise Him for something beautiful in creation.
confess sins and ask forgiveness
give thanks for the good that God's done.
Ask them to pray short prayers for one topic at a time. This is the natural way we carry on conversation and is the best way to carry on a group conversation with God. Remind them that they can pray as many times as they want, but to pray short prayers about one topic at a time. This will allow other members of the group to join that prayer.