Here's an old trick for arranging the agenda. Start with something easy to give the group a sense of accomplishment right up front. If you have a difficult item on the agenda, put it in the middle. And be sure to put an item at the end that will allow the group to end on a good note.
Pay attention to the room. It really does make a difference. Is the lighting appropriate - right amount, cheerful but not institutional. Can you imagine a way to arrange the room so it feels more conducive to fellowship, and not so much like a class room or a board meeting? Have you ever put toys on the table for people to fiddle with while they listen? This can make a huge difference for people who are not used to sitting in meetings, or who need to be doing something with their hands while they think. Lighten the mood - you can attend to serious business while helping the group stay relaxed and energized if you really take pains to make the meeting space pleasant.
When things are getting stuck in some way, ask for a moment of silence to allow the group to settle, to tune in, to be quiet and listen to the Spirit. Give people an opportunity to step back from the tension, and tune in to God. Ask people to pray, silently or aloud. Listen. Give the Spirit space to operate. Deacons have difficult things to discern sometimes, and if the conversation is going sideways, it can really help to give folks permission to take a deep breath and pray for wisdom and grace.