Something that works great with children is making animal sounds. For example, you can do your normal modulations and arpeggio exercises with the “moo” syllable like a cow or a “baa” syllable for a sheep while the kids also act like that particular animal.
It’s not only about singing!
A good warm-up session isn’t only about physically warming up the parts of your body that are used for singing, it must also get you in the mood for a performance or rehearsal emotionally and psychologically. As any musician knows, you cannot practice effectively if you aren’t fully engaged in what you’re doing. That’s why it’s important to remember that attitude counts.
Warming up isn’t only about singing. There are many warm-up exercises for singing that do not involve singing at all. If you practice yawning, or fake sneezing, you are actually practicing the correct position to get the ideal resonance when singing. Clapping, stomping your feet, and diverse hand gestures can get a choir pumped up for practice, boost teamwork, and help reinforce a sense of rhythm. Incorporating simple dance moves into a choir warm-up can help greatly with breath control and educating the diaphragm.
Don’t be afraid of being silly.
The best way to get music students to keep practicing is by making music fun. There is a time for being serious and demanding, but warm-up and cool-down time is not it. You can lighten the mood and make rehearsal fun by playing around with the repertoire you are singing. Take a part of a song you are working on and as a warm-up sing it really slow and gradually make it faster, until it becomes a blur and comes apart. You can also do this with a simple scale and arpeggio combination, pushing them to sing it faster and faster.