So I adjust my warm ups accordingly:
– Nasal scales/arpeggios for the chest voice
– Continuous sirens for the head voice, which avoids any crackle as it has to be a pure tone
– Encourage the student to drop/raise the larynx for each exercise so they can feel how their tone changes and how to get clarity this way
– Get them to feel comfortable with a shouty voice (imagine calling over to someone on the other side of the street) as this triggers the reflex of power your voice makes