Mistakes will occur more often when you do not leave enough time to prepare your presentation, edit it and run through it once or twice with the worship team. A rushed job will be noticeable by the errors it contains, because not everything was checked and double-checked before going live. Give yourself enough time to do everything the right way. Always check over your work and have a margin of time just in case something needs to be changed at the last minute.
Be at the rehearsal on time and have everything prepared in advance whenever possible. Familiarize yourself with the worship set, songs and order of service. Check to make sure everything is working properly, especially all the pieces of media. You can never be too prepared when it comes to worship projection. Do not underestimate the preparation time needed to put together a flawless presentation. It takes dedication and sacrifice to make sure your job is done to the highest standards.
To learn more worship lyric projection best practices read The Worship Media Handbook.