Preparation involves two sub-points:
In some respects, this is the harder of the two. Most of us have to work the entire day and then come to rehearsal. Some suggestions:
Don’t stay up late on Saturday night. Try to arise by 6:30 on Sunday AM; begin singing as soon as feasible. Again, "vocalises" are good, but singing hymns is an excellent way to prepare – both spiritually and physically. Then, arrive at church by 9:00 AM and participate fully in the choir warm0up. If all the choir cooperates in this, our pitch and sound will improve greatly!