I recently purchased a DVD called Daily Workout for a Beautiful Voice to use with my choir. Although not every chorister takes voice lessons, a director can teach a lot of technique in the warm-up time. The choir demonstrating the warm-ups in the DVD is a treble high school choir, but the warm-ups are appropriate for any age choir. I am very pleased with the tone and vitality that I am hearing from my choir as a result of these warm-ups. There is movement (which is done in place - no roaming around the room) for each warm-up which is very helpful in releasing a great sound and preventing tension.
In fact, I have been so impressed with these warm-ups that I have begun to use them in my private voice studio. A few young high school girls are finally giving me sound that I have never heard from them - I think the movements with the warm-ups are the key. Something has clicked and I am thrilled!
From the booklet that accompanies the video -
"The Daily Workout exercises are designed to help singers develop a free warm tone, to sing with ease, and to increase range. They are clustered into five dynamic groupings. The sequence of these groupings is significant. The concepts focused upon in each group progressively build upon one another."
Let me know if this DVD helps you with your choir or your own voice students!