Write simple melodies that use a majority of stepwise motion in the lines. It is important to avoid skips and leaps in the melody as this can create performance problems.
Write music that is within a major or minor key. Do not write music that is highly chromatic or that makes use of many accidentals. Children are just learning about music, and asking a group of children to sing highly chromatic music will prove difficult for them.
Write each individual part in a close range. Do not attempt to write melodies that go past the range of an octave. To make it even easier, keep the entire range of the melody to a fifth or less.
Write short phrases that will be easily singable in a single breath.
Use predictable chord progressions. Children can easily learn and sing simple progressions, such as I-IV-V-I, or I-V- I.
Provide rest for the singers so that their voices don't tire out. This can be done by alternating lines between several groups of singers.
Provide breathe marks in the music to let the children know when to breathe. This will help with phrasing as well.
Write short pieces that are no longer than 5 to 6 minutes in duration.