During the offering. Introduce news songs in the middle not at the beginning of a set. If possible, do not begin and end with a new song, it is too distracting. Place the new song in the middle, after you have connected with the congregation. Use a worship team.
Worship teams provide stability for the worship leader and support for the congregation.
Team members also often improved on the worship leader's ideas during rehearsal and provide valuable critiques after the service. Sound booths are vital to effective worship. Seek in your sound booth a person who technically knows the sound board and has a musical ear. That combination is rare. Individuals are often strong in one area but not in both.