At first, your group might really struggle to play without you – give them time to adjust. (This is great evidence of previous inadequate listening/understanding and unhealthy reliance on visual assistance). Besides, the transfer of personal ownership and accountability can, at first be daunting!
Resist the temptation to beat time, cue players in, or even look at them before they enter. Their correct entry is evidence they are engaged in the sound while they are ‘resting’. Rehearsing in scattered format is even better for this! The key for beginning together without you is found in 'listening for the breath'. Breathe together to start together.
Coach the student’s listening attention toward the most active part, listening to the internals, sideways as well as to the bass line and harmonic progression.
Hand over responsibility for keeping the tempo to those with the most active part. Energise the long notes! These are important principles to transfer when you do conduct again.
In many textures, there is a ‘metronome’ role played by someone in the ensemble – assist them in finding it.
This strategy works; even through changes of tempi and with fermati; with, and without caesura!
Make allowance for things to come apart – let them! Give your students permission to restore order on their own – you will need this skill in performance.
Allowing your group to perform perform without you allows one to hear more, or not, of what is happening. Move around your rehearsal space, getting further away to check the balance as the audience hears it.
When you are satisfied that you can trust your ensemble enough, plan to have your them perform something without you. This is a great way for personal discipline in your rehearsal style; enabling students take greater responsibility for the success of the performance, thus receiving the positive recognition, which should be theirs.
You will find that over time, the sound of the group matures as they adapt to self-directed exercises. Synchronisation and balance improves, as does tone and intonation. They should now be ready to appreciate how this exercise improves ensemble intonation and integration.
When your students begin to self-correct their own pitch, balance and rhythm errors, you will know that these strategies are beginning to pay dividends on your investment in this exercise.