Here is a warm-up exercise for six voice groups, making arpeggios in minor. The choir members will be stacking thirds: the root, the third, the fifth, the seventh, the none and finally the eleven. To make the exercise challenging for the men’s voices as well, the chord is repeated from top to bottom.
You might do this exercise with just one chord. But if you really want to have an exciting exercise, you might repeat the chord on scale degrees I-IV-I:
Optionally, you might expand the exercise to include the scale degree V. Make sure you will make that a minor chord as well, though in general you might expect a major chord on the fifths scale degree.