What are some guidelines for leading a church in prayer?

Use “we,” not “I.” You’re praying on behalf of everyone in the room, not just yourself.
Carefully consider beforehand what you are going to say. Whether you read the prayer, use notes, or have no written aid, give careful thought beforehand to what you are going to say. Ecclesiastes 5:2: “Be not rash with your mouth, nor let your heart be hasty to utter a word before God, for God is in heaven and you are on earth. Therefore let your words be few.”
Use biblical ideas and language. A prayer soaked in the ideas and language of Scripture will best edify the people of God, so use the Bible as a guide as you address God on behalf of the whole church.
Keep things concise and to the point. Avoid wordy repetition and rambling. Matthew 6:7: “And when you pray, do not heap up empty phrases as the Gentiles do, for they think that they will be heard for their many words.”