It’s no secret that good technique is key to singing well.
Once you have established a firm foundation on which to build your voice, you should then, and only then, venture on to extreme singing.
What is extreme singing? Any coordination that requires the voice to go beyond the basic set-up of a balanced mix between your low and high register.
I always “balance” my voice in warm-up. I ensure I can easily soar and siren through my entire range (mine is D2 to D5). I usually start with lip bubbles and vary the vowel/consonant combinations daily.
One of my main goals when warming up is gain insight into my breath control and cord closure. Depending on my “energy” and focus on any given day, this can vary. Warming up gives me the cues I need to know how my voice is going to be in performance.
If you have been singing all your life, odds are you can be ready to sing in fine form in a matter of minutes. However, if you don’t sing every day, it may very well take you 15 to 20 minutes of warm-up before you are ready to sing well.