The best time to practice is as soon as possible.
I just sent a message to the Michigan All-State Jazz Choir: “We perform ONE MONTH FROM TODAY! Keep Practicing!!!!
The impulse to wait as long as possible to practice is strong; most of us apparently need to feel urgency as a motivating tool. But the best time to practice is as far from the performance as possible, so you have as much time as possible to fine tune and perfect your art.
As teachers, it is our job to create the sense of urgency so that the students who don’t have that mindset ingrained can still get their practicing done earlier.
I’ve used lots of different tools: memorization and quartet tests, preview performances, practice logs, etc. There’s not just one lever to pull.
The best tool is one that creates urgency for the singers while empowering them with the tools they need to succeed.